If you have ever tried to build a tool to find wasted AWS spend, you learn quickly that the API calls are the easy part. DescribeVolumes , GetMetricData , a few paginated List calls, and you are done. The hard part is deciding when you are actually allowed to put a dollar sign next to a finding, because a wrong number is worse than no number. A tool that says you could save about $70 a month and turns out to be off by half teaches the reader to ignore it completely. So I set a strict rule...