This is definitely on our list!
In the meantime, please create a budget which will trigger a script (e.g. Automation, Functions, or Logic Apps) via action groups to shutdown or delete resources based on your specific needs.Raphael commented
Users can now set budgets at Subscriptions and Resource Group scopes in cost management. We also have APis that are available to do the same. Enterprise customer can also set budgets for their commercial scopes like Enrollment, Departments and Accounts.
https://aka.ms/costmgmt/videos (there is a video on creating budgets)