Oracle has fantastic budget tools. Not just "you've passed your budget", but "you're forecast to pass your budget in 22 days before the month is up". And you can couple it with quotas to create hard budgets.

AWS has decent tools in this regard, but it pales compared to Oracle. Azure is a product I've never used with any scale (just small projects), but the fact that it actually costs money to setup alerts is gross (and morally reprehensible). Even if it's a trivial amount, that alone just sours the product in my eyes. I mean, already Azure is pretty uncompetitive unless you're running on free credits, as Troy apparently is (purportedly some $13K per year, so unsure what the pitch for donations to cover a bill is about).