>The very simple problem is that there is no way of providing hard spend caps without giving you the opportunity to bring down your whole production environment when the cap is met.

And why is that a problem? And how different is that from "forgetting" to pay your bill and having your production environment brought down?

> And how different is that from "forgetting" to pay your bill and having your production environment brought down?

AWS will remind you for months before they actually stop it.