I had a personal $400 learning experience with Amazon. They did refund it. My last company had a low-5-figure surprise a few years ago. Some of that could be considered their fault (alerts were sent to someone on vacation), but again, the refusal to allow the option of a "hit a limit, pull the plug" option is what causes this.
Of course, there's also the opposite scenario "So here we were, having the best sales day in our history, and suddenly Amazon pulled the plug on our servers because we went over our authorized limit! We lost 5-figures of sales that day. Sure, they sent us warnings, but the alerts went to someone on vacation... but why wouldn't they let us exceed the limit for a bit before they pull the plug"
nobody says that the hard limit should be there for everybody, but I SHOULD be able to hit a checkbox that says "no matter what happens, runaway CPU, somebody DDOSing me with traffic, runaway disk, I do not want to be responsible for more than $x/month"
Personally this is the main reason why I have never considered using AWS for my small projects, but maybe this is an intentional choice by Amazon, to keep away "hobbyists" and only go after companies where an extra $1k in AWS bills this month is just a blip on the radar...
I had a personal $400 learning experience with Amazon. They did refund it. My last company had a low-5-figure surprise a few years ago. Some of that could be considered their fault (alerts were sent to someone on vacation), but again, the refusal to allow the option of a "hit a limit, pull the plug" option is what causes this.