A cli tool for sampling recent EC2 spot pricing data and showing a histogram of the results. An analysis of relative cost for that period is also performed based on the actual per-hour pricing.
$ ec2spot -days 30 -instance m4.large -region us-east-1
Instance Type: M4 Large
VCPU: 2
Memory: 8.00
On-Demand Price: 0.108000
0.0134-0.4289 100% ████████████████████▏ 39791
0.4289-0.8445 0% ▏
0.8445-1.26 0.0126% ▏ 5
Spot price for 742 hours would be $27.77 (~$0.03743 hourly) vs $80.14 on-demand (65.35% difference)