> Even having the option of a hard spend limit would be hazardous, because accounting teams might push the use of such tools, and thereby risk data loss incidents when problems happen.

This is an interesting point and something I can totally imagine happening! I guess if you have fixed spending limits in a large enough organisation, you lose some of the benefit of cloud infrastructure. Convincing a (metaphorically) remote Finance department to increase your fixed spending limit is probably a tougher task than ordering a load of new hardware!