That and post-scarcity doesn't mean "zero scarcity". Like if someone wanted to create a picard funkpop the size of a planet, I don't think they'd be allowed the resource budget.
It's like how it doesn't matter where you live, if you want to buy on the silk road, you need bitcoin. Presumably even the federation can't just make latinum whenever they please, or we wouldn't see them haggle with it. Although, it would be fun to see that they could and just take the responsibility of not crashing non-federation cultures entire economies very seriously, either out of respect or treaty.
Damnit, I want a LD episode where the crew is frustrated and desperately wants to just "buy" their problem away but can't because an economist at command says it'll mean they have to rescue all these non-federation colonies that are currently self sufficient. Come to think of it it's right there with the "you break it you own it" concept of the prime directive.