diff --git a/src/price/AbstractPrice.php b/src/price/AbstractPrice.php
index bba98577..0aefd2b4 100755
--- a/src/price/AbstractPrice.php
+++ b/src/price/AbstractPrice.php
@@ -53,7 +53,7 @@ abstract class AbstractPrice implements PriceInterface, ChargeModifier
     protected $plan;
 
     public function __construct(
-                            $id,
+        $id,
         TypeInterface $type,
         TargetInterface $target,
         PlanInterface $plan = null
@@ -137,10 +137,45 @@ public function calculateSum(QuantityInterface $quantity): ?Money
 
     public function jsonSerialize(): array
     {
-        $res = array_filter(get_object_vars($this));
-        unset($res['plan']);
+        $data = [
+            'id' => $this->id,
+            'class' => (new \ReflectionClass($this))->getShortName(),
+            'type' => $this->getType()->getName(),
+            'type_id' => $this->getType()->getId(),
+            'object_id' => $this->getTarget()->getId(),
+            'object' => [
+                'id' => $this->getTarget()->getId(),
+                'name' => $this->getTarget()->getName(),
+                'type' => $this->getTarget()->getType(),
+            ],
+            'plan_id' => $this->getPlan()?->getId(),
+        ];
+
+        if ($this instanceof PriceWithSubpriceInterface) {
+            $data['subprice'] = $this->getSubprices()->values();
+        }
+
+        if ($this instanceof PriceWithRateInterface) {
+            $data['rate'] = $this->getRate();
+        }
+
+        if ($this instanceof PriceWithUnitInterface) {
+            $data['unit'] = $this->getUnit()->getName();
+        }
+
+        if ($this instanceof PriceWithCurrencyInterface) {
+            $data['currency'] = $this->getCurrency()->getCode();
+        }
+
+        if ($this instanceof PriceWithSumsInterface) {
+            $data['sums'] = $this->getSums()->values();
+        }
+
+        if ($this instanceof PriceWithQuantityInterface) {
+            $data['quantity'] = $this->getPrepaid()->getQuantity();
+        }
 
-        return $res;
+        return $data;
     }
 
     /**
diff --git a/src/price/EnumPrice.php b/src/price/EnumPrice.php
index d7a5a5bc..a2eabb45 100644
--- a/src/price/EnumPrice.php
+++ b/src/price/EnumPrice.php
@@ -26,31 +26,22 @@
  *
  * @author Andrii Vasyliev <sol@hiqdev.com>
  */
-class EnumPrice extends AbstractPrice
+class EnumPrice extends AbstractPrice implements PriceWithSumsInterface, PriceWithCurrencyInterface, PriceWithUnitInterface
 {
-    /**
-     * @var UnitInterface
-     */
-    protected $unit;
+    protected UnitInterface $unit;
 
-    /**
-     * @var Currency
-     */
-    protected $currency;
+    protected Currency $currency;
 
-    /**
-     * @var array quantity => total sum for the quantity
-     */
-    protected $sums;
+    protected Sums $sums;
 
     public function __construct(
-                            $id,
+        $id,
         TypeInterface $type,
         TargetInterface $target,
         ?PlanInterface $plan,
         UnitInterface $unit,
         Currency $currency,
-        array $sums
+        Sums $sums,
     ) {
         parent::__construct($id, $type, $target, $plan);
         $this->unit = $unit;
@@ -58,17 +49,17 @@ public function __construct(
         $this->sums = $sums;
     }
 
-    public function getUnit()
+    public function getUnit(): UnitInterface
     {
         return $this->unit;
     }
 
-    public function getCurrency()
+    public function getCurrency(): Currency
     {
         return $this->currency;
     }
 
-    public function getSums()
+    public function getSums(): Sums
     {
         return $this->sums;
     }
@@ -80,7 +71,7 @@ public function calculateSum(QuantityInterface $quantity): ?Money
     {
         $usage = $this->calculateUsage($quantity)->getQuantity();
 
-        foreach ($this->sums as $value => $price) {
+        foreach ($this->sums->values() as $value => $price) {
             if ((string) $value === (string) $usage) {
                 return new Money($price, $this->currency);
             }
diff --git a/src/price/HasMoney.php b/src/price/HasMoney.php
new file mode 100644
index 00000000..e11b1ca1
--- /dev/null
+++ b/src/price/HasMoney.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace hiqdev\php\billing\price;
+
+use Money\Currency;
+use Money\Money;
+
+trait HasMoney
+{
+    protected Money $price;
+
+    public function getPrice(): Money
+    {
+        return $this->price;
+    }
+
+    public function getCurrency(): Currency
+    {
+        return $this->price->getCurrency();
+    }
+}
diff --git a/src/price/HasQuantity.php b/src/price/HasQuantity.php
new file mode 100644
index 00000000..f407eb42
--- /dev/null
+++ b/src/price/HasQuantity.php
@@ -0,0 +1,25 @@
+<?php declare(strict_types=1);
+
+namespace hiqdev\php\billing\price;
+
+use hiqdev\php\units\QuantityInterface;
+use hiqdev\php\units\UnitInterface;
+
+trait HasQuantity
+{
+    /**
+     * @var QuantityInterface prepaid quantity also implies Unit
+     * XXX cannot be null cause Unit is required
+     */
+    protected QuantityInterface $prepaid;
+
+    public function getPrepaid(): QuantityInterface
+    {
+        return $this->prepaid;
+    }
+
+    public function getUnit(): UnitInterface
+    {
+        return $this->prepaid->getUnit();
+    }
+}
diff --git a/src/price/PriceFactory.php b/src/price/PriceFactory.php
index a771f685..02e794d8 100644
--- a/src/price/PriceFactory.php
+++ b/src/price/PriceFactory.php
@@ -77,9 +77,9 @@ public function findMethodForClass($class)
         throw new FailedCreatePriceException("unknown class: $class");
     }
 
-    public function createEnumPrice(PriceCreationDto $dto)
+    public function createEnumPrice(PriceCreationDto $dto): EnumPrice
     {
-        return new EnumPrice($dto->id, $dto->type, $dto->target, $dto->plan, $dto->unit, $dto->currency, $dto->sums);
+        return new EnumPrice($dto->id, $dto->type, $dto->target, $dto->plan, $dto->unit, $dto->currency, new Sums($dto->sums));
     }
 
     public function createRatePrice(PriceCreationDto $dto)
diff --git a/src/price/PriceInvalidArgumentException.php b/src/price/PriceInvalidArgumentException.php
new file mode 100644
index 00000000..309e5725
--- /dev/null
+++ b/src/price/PriceInvalidArgumentException.php
@@ -0,0 +1,9 @@
+<?php declare(strict_types=1);
+
+namespace hiqdev\php\billing\price;
+
+use hiapi\exceptions\HiapiException;
+
+class PriceInvalidArgumentException extends HiapiException
+{
+}
diff --git a/src/price/PriceWithCurrencyInterface.php b/src/price/PriceWithCurrencyInterface.php
new file mode 100644
index 00000000..f27d273b
--- /dev/null
+++ b/src/price/PriceWithCurrencyInterface.php
@@ -0,0 +1,10 @@
+<?php declare(strict_types=1);
+
+namespace hiqdev\php\billing\price;
+
+use Money\Currency;
+
+interface PriceWithCurrencyInterface
+{
+    public function getCurrency(): Currency;
+}
diff --git a/src/price/PriceWithMoneyInterface.php b/src/price/PriceWithMoneyInterface.php
new file mode 100644
index 00000000..33d39b77
--- /dev/null
+++ b/src/price/PriceWithMoneyInterface.php
@@ -0,0 +1,10 @@
+<?php declare(strict_types=1);
+
+namespace hiqdev\php\billing\price;
+
+use Money\Money;
+
+interface PriceWithMoneyInterface extends PriceWithCurrencyInterface
+{
+    public function getPrice(): Money;
+}
diff --git a/src/price/PriceWithQuantityInterface.php b/src/price/PriceWithQuantityInterface.php
new file mode 100644
index 00000000..5416c08f
--- /dev/null
+++ b/src/price/PriceWithQuantityInterface.php
@@ -0,0 +1,10 @@
+<?php declare(strict_types=1);
+
+namespace hiqdev\php\billing\price;
+
+use hiqdev\php\units\QuantityInterface;
+
+interface PriceWithQuantityInterface extends PriceWithUnitInterface
+{
+    public function getPrepaid(): QuantityInterface;
+}
diff --git a/src/price/PriceWithRateInterface.php b/src/price/PriceWithRateInterface.php
new file mode 100644
index 00000000..d7ca87a6
--- /dev/null
+++ b/src/price/PriceWithRateInterface.php
@@ -0,0 +1,8 @@
+<?php declare(strict_types=1);
+
+namespace hiqdev\php\billing\price;
+
+interface PriceWithRateInterface
+{
+    public function getRate(): float;
+}
diff --git a/src/price/PriceWithSubpriceInterface.php b/src/price/PriceWithSubpriceInterface.php
new file mode 100644
index 00000000..1faf9304
--- /dev/null
+++ b/src/price/PriceWithSubpriceInterface.php
@@ -0,0 +1,12 @@
+<?php declare(strict_types=1);
+
+namespace hiqdev\php\billing\price;
+
+use hiqdev\billing\hiapi\price\SubPrices;
+
+interface PriceWithSubpriceInterface
+{
+    public function getSubprices(): SubPrices;
+
+    public function getSubprice(string $currencyCode);
+}
diff --git a/src/price/PriceWithSumsInterface.php b/src/price/PriceWithSumsInterface.php
new file mode 100644
index 00000000..fe6c6619
--- /dev/null
+++ b/src/price/PriceWithSumsInterface.php
@@ -0,0 +1,8 @@
+<?php declare(strict_types=1);
+
+namespace hiqdev\php\billing\price;
+
+interface PriceWithSumsInterface
+{
+    public function getSums(): Sums;
+}
diff --git a/src/price/PriceWithThresholdsInterface.php b/src/price/PriceWithThresholdsInterface.php
new file mode 100644
index 00000000..1a8a2bad
--- /dev/null
+++ b/src/price/PriceWithThresholdsInterface.php
@@ -0,0 +1,8 @@
+<?php declare(strict_types=1);
+
+namespace hiqdev\php\billing\price;
+
+interface PriceWithThresholdsInterface
+{
+    public function getThresholds(): ProgressivePriceThresholdList;
+}
diff --git a/src/price/PriceWithUnitInterface.php b/src/price/PriceWithUnitInterface.php
new file mode 100644
index 00000000..63136272
--- /dev/null
+++ b/src/price/PriceWithUnitInterface.php
@@ -0,0 +1,10 @@
+<?php declare(strict_types=1);
+
+namespace hiqdev\php\billing\price;
+
+use hiqdev\php\units\UnitInterface;
+
+interface PriceWithUnitInterface
+{
+    public function getUnit(): UnitInterface;
+}
diff --git a/src/price/ProgressivePrice.php b/src/price/ProgressivePrice.php
index 6bb4ce7a..baabf712 100644
--- a/src/price/ProgressivePrice.php
+++ b/src/price/ProgressivePrice.php
@@ -14,13 +14,14 @@
 use Money\Money;
 use Money\Parser\DecimalMoneyParser;
 
-class ProgressivePrice extends AbstractPrice
+class ProgressivePrice extends AbstractPrice implements PriceWithThresholdsInterface,
+    PriceWithMoneyInterface,
+    PriceWithQuantityInterface
 {
-    protected ProgressivePriceThresholdList $thresholds;
-
-    protected Money $price;
+    use HasMoney;
+    use HasQuantity;
 
-    protected QuantityInterface $prepaid;
+    protected ProgressivePriceThresholdList $thresholds;
 
     public function __construct(
         $id,
@@ -30,7 +31,8 @@ public function __construct(
         Money $price,
         ProgressivePriceThresholdList $thresholds,
         ?PlanInterface $plan = null
-    ) {
+    )
+    {
         parent::__construct($id, $type, $target, $plan);
         $this->thresholds = $thresholds;
         $this->price = $price;
@@ -42,16 +44,6 @@ public function getThresholds(): ProgressivePriceThresholdList
         return $this->thresholds;
     }
 
-    public function getPrepaid(): QuantityInterface
-    {
-        return $this->prepaid;
-    }
-
-    public function getPrice(): Money
-    {
-        return $this->price;
-    }
-
     /**
      * @inheritDoc
      */
diff --git a/src/price/RatePrice.php b/src/price/RatePrice.php
index 77a14e9e..71fff5f2 100644
--- a/src/price/RatePrice.php
+++ b/src/price/RatePrice.php
@@ -24,10 +24,9 @@
  *
  * @author Andrii Vasyliev <sol@hiqdev.com>
  */
-class RatePrice extends AbstractPrice
+class RatePrice extends AbstractPrice implements PriceWithRateInterface
 {
-    /** @var float */
-    protected $rate;
+    protected float $rate;
 
     public function __construct(
         $id,
diff --git a/src/price/SinglePrice.php b/src/price/SinglePrice.php
index 6010eb7f..320f6ab2 100644
--- a/src/price/SinglePrice.php
+++ b/src/price/SinglePrice.php
@@ -27,21 +27,13 @@
  *
  * @author Andrii Vasyliev <sol@hiqdev.com>
  */
-class SinglePrice extends AbstractPrice
+class SinglePrice extends AbstractPrice implements PriceWithQuantityInterface, PriceWithMoneyInterface
 {
-    /**
-     * @var QuantityInterface prepaid quantity also implies Unit
-     * XXX cannot be null cause Unit is required
-     */
-    protected $prepaid;
-
-    /**
-     * @var Money
-     */
-    protected $price;
+    use HasMoney;
+    use HasQuantity;
 
     public function __construct(
-                            $id,
+        $id,
         TypeInterface $type,
         TargetInterface $target,
         PlanInterface $plan = null,
@@ -53,16 +45,6 @@ public function __construct(
         $this->price    = $price;
     }
 
-    public function getPrepaid()
-    {
-        return $this->prepaid;
-    }
-
-    public function getPrice()
-    {
-        return $this->price;
-    }
-
     /**
      * {@inheritdoc}
      */
diff --git a/src/price/Sums.php b/src/price/Sums.php
new file mode 100644
index 00000000..2d10117a
--- /dev/null
+++ b/src/price/Sums.php
@@ -0,0 +1,44 @@
+<?php declare(strict_types=1);
+
+namespace hiqdev\php\billing\price;
+
+final readonly class Sums implements \JsonSerializable
+{
+    /**
+     * @param int[]|null $values quantity => total sum for the quantity
+     */
+    public function __construct(private ?array $values)
+    {
+        if (!empty($this->values)) {
+            $this->validate($this->values);
+        }
+    }
+
+    private function validate(array $sums): void
+    {
+        if ($sums) {
+            foreach ($sums as $value) {
+                if (!is_numeric($value)) {
+                    throw new PriceInvalidArgumentException('Invalid value for sums parameter');
+                }
+            }
+        }
+    }
+
+    public function values(): ?array
+    {
+        return $this->values;
+    }
+
+    public function getMinSum(): int|string
+    {
+        return min($this->values);
+    }
+
+    public function jsonSerialize(): ?array
+    {
+        return [
+            'values' => $this->values,
+        ];
+    }
+}
diff --git a/src/price/SumsHydrator.php b/src/price/SumsHydrator.php
new file mode 100644
index 00000000..6ce98fe9
--- /dev/null
+++ b/src/price/SumsHydrator.php
@@ -0,0 +1,27 @@
+<?php declare(strict_types=1);
+
+namespace hiqdev\php\billing\price;
+
+use hiqdev\DataMapper\Hydrator\GeneratedHydrator;
+
+class SumsHydrator extends GeneratedHydrator
+{
+    public function hydrate(array $data, $object): object
+    {
+        if (!isset($data['sums'])) {
+            throw new PriceInvalidArgumentException('Missing required key: sums');
+        }
+        return new Sums($data['sums']);
+    }
+
+    /**
+     * {@inheritdoc}
+     * @param Sums $object
+     */
+    public function extract($object): array
+    {
+        return [
+            'values'  => $object->values(),
+        ];
+    }
+}
diff --git a/tests/support/plan/CertificatePlan.php b/tests/support/plan/CertificatePlan.php
index aa3b8513..278af07f 100644
--- a/tests/support/plan/CertificatePlan.php
+++ b/tests/support/plan/CertificatePlan.php
@@ -14,6 +14,7 @@
 use hiqdev\php\billing\customer\Customer;
 use hiqdev\php\billing\plan\Plan;
 use hiqdev\php\billing\price\EnumPrice;
+use hiqdev\php\billing\price\Sums;
 use hiqdev\php\billing\target\Target;
 use hiqdev\php\billing\type\Type;
 use hiqdev\php\units\Unit;
@@ -110,9 +111,9 @@ public function getRawPrice($action)
         return $this->getRawPrices($action->getType(), $action->getTarget())[$years];
     }
 
-    public function getRawPrices($type, $target)
+    public function getRawPrices($type, $target): Sums
     {
-        return $this->rawPrices[$this->getRawPriceKey($type, $target)];
+        return new Sums($this->rawPrices[$this->getRawPriceKey($type, $target)]);
     }
 
     /**
diff --git a/tests/unit/price/PriceFactoryTest.php b/tests/unit/price/PriceFactoryTest.php
index 99bfdf10..b89a6bc0 100644
--- a/tests/unit/price/PriceFactoryTest.php
+++ b/tests/unit/price/PriceFactoryTest.php
@@ -57,7 +57,7 @@ public function testEnumPrice()
         $this->assertSame($this->enum,      $price->getType());
         $this->assertSame($this->target,    $price->getTarget());
         $this->assertSame($this->unit,      $price->getUnit());
-        $this->assertSame($this->sums,      $price->getSums());
+        $this->assertSame($this->sums,      $price->getSums()->values());
         $this->assertSame($this->price->getCurrency(),  $price->getCurrency());
     }