i looked into this a year ago and there was no such thing available (there is https://docs.microsoft.com/en-us/azure/cost-management-billi... but that is not really a spending limit, it's more like in some cases you get credits from microsoft and when you have spent all the credits they stop things for you). i mean a system where you pay monthly what you consumed, and you can set a limit, and the provider guarantees that you do not have to pay more than the limit.

but maybe i overlooked something, so if you know more about this, please tell.

btw. fly.io has a kind-of spending-limit, you can preload some credit into the account and when that is spent you are relatively safe ( https://community.fly.io/t/can-i-set-a-billing-limit-per-mon... )