I'm sure I'm preaching to the choir, but there really should be some safeguards that can trip along the way for what is clearly an individual account. Also there should always be hard limits available to turn on (maybe turned on by default).

Perhaps some kind of "we only let your bill be X% higher than the rolling average for your account" coupled with "First time you hit $10, $50, $100, $500, $1K .... firebreaks, alarms coupled with auto-stop/shutdown if you don't respond with a day or two". All of this would be available to turn off so it would just serve as a safety net.