What if instead of gold and magic, you rewarded reputation?
The party that saved the merchant's caravan gets recognized in every shop in the district. "Oh, you're the ones who fought off those bandits! Let me show you the good stuff I keep in the back." That discount is worth more than gold because it's personal.
Information can be treasure.
Maps to hidden 4 locations, secrets about NPC motivations, blackmail material, prophecies. When the party finds the old wizard's journal and learns that the kindly mayor is actually a shapeshifter, that's not gold and that's not a magic sword, but it just changed everything.
Resources tell stories.
A loyal NPC who owes them a favor. A safe house where they can lie low. A trained animal. A boat that opens up coastal adventures. These rewards change what's possible, not just the numbers on the character sheet.
Story progress itself is reward. The real treasure was stopping the ritual before the demon manifested. The real treasure was saving the village. The real treasure was earning the king's trust so he'll listen when you warn him about the coming invasion.
Here's how this looks in practice. The party defeats a necromancer terrorizing a region. A generous DN gives them his treasure hoard: 10,000 gold and three magic items. A savvy DN gives them the village's gratitude, which means free lodging whenever they return, a contact who sends word when trouble brews, and a reputation that spreads. Three sessions later in a different city, someone recognizes them: "You're the ones who killed the Dreadmoor Necromancer! Please, we have a problem you might understand..." The reward from that first quest just generated a new quest hook organically.
That's an economy that doesn't inflate. It expands.