Lower your AWS costs (up to 90%!) by automating the use of spot instances
If you’re using EC2 and paying big bucks to do so, you owe it to yourself to check out AutoSpotting:
Once installed and enabled by tagging existing on-demand AutoScaling groups, AutoSpotting gradually replaces their on-demand instances with spot instances that are usually much cheaper, at least as large and identically configured to the group’s members, without changing the group configuration in any way. For your peace of mind, you can also keep running a configurable number of on-demand instances given as percentage or absolute number.