For everyone here, you should be able to use quotas in order to set actual limits, you can lower them yourself as a practical solution.

https://docs.cloud.google.com/docs/quotas/view-manage

Quotas are real time or near real time.

Real time spend limits are probably never going to happen. Actual $ amounts are calculated by a centralized billing system offline in batch.

It sounds easy but it’s bonkers complicated, because of things like discounts, free tiers, committed usage, currency conversions and having to support every payment and deal structure in GCP.

Individual eng teams rarely actually think in dollar amounts, they think in the abstraction which is quotas.