Economics is never addressed in Star Trek, but I could see an administrative solution to such issues. Inside Starfleet there is little to no money, as replicators are readily available. The power supply and replicators themselves would be there anyway, so giving the crew access is a freebie. And the civilian society on advanced worlds would be similar, with manufacture of material possessions too cheap to worry about.

On worlds still using money with which Starfleet interacts, the local administration could simply make an arrangement with the local purveyors of desired goods to cover their tabs, perhaps at least partly in trade. The needs and wants of the Starfleet crew members would likely be only social, such as hanging out at the local bar.

There would be temptation by the locals to pressure the crew-members to give them replicator-made goods, and by the local proprietors to lie about bar tabs, but its nothing our current system doesn't deal with.