There's a property to represent the budget for a project: https://wikidata.org/wiki/Property:P2769 So the triple store is perfectly capable of storing that kind of data. If you don't find what you're looking for, it just means nobody cared enough to add it yet.

I adapted one of the example queries to show the most recent entities with a budget: https://query.wikidata.org/#%23%20All%20items%20with%20a%20p...

Looks like mostly research grants. My guess is that someone wrote an integration to add new research grants to Wikidata as soon as they're published.