I found that project recently https://code.google.com/p/amazon-pricewatcher/ https://code.google.com/p/amazon-pricewatcher/ It's old, and probably won't work.

I found that project recently https://code.google.com/p/amazon-pricewatcher/ https://code.google.com/p/amazon-pricewatcher/ It's old, and probably won't work. But the idea is interesting. It monitors your AWS account, and shutdowns EC2 instances/removes S3 files if your bill goes up. It could be interesting to re-write it using boto. Maybe even make it simpler: If the bill goes over a "hard" limit, shutdown anything that can be shutdown (but don't delete anything!). I guess I would prefer to have a short downtime than a crazy bill. Added to a well setup alert monitoring, it could be a great way to limit crazy billing. @WestCoastJustin point to use dedicates roles account seems like a quite import thing as well. I think I would also trend to avoid large-range ASG.