Most RPGs provide a ton of loot to sell. In 'Gothic', you didn't have money, but traded magical ore as hard currency aka sound money. But if the supply of tradeable items with a vendor was up, tough luck. Nothing to get from that person anymore. (Ignoring exploits like waiting for swords to spawn in the blacksmith's inventory so he can play his sharpening the sword animation.)
What games usually don't have is a real market. Why can I beat green slime in the forest and obtain e.g. leaves (craft item) ad infinitum, and sell them at a fixed price forever? When the market is saturated on leaves, make the price go down. Eventually you'll have to trade in a sack of leaves for an apple because everyone has leaves coming out of their ears thanks to you selling them this crap.
That would tackle not drowning in infinite money. It'd also introduce a simulation of trading that rewards supply and demand considerations in different locations, which may not be what you're looking to implement.
Look for opportunities to spend more money. A night at the inn for healing, but not like in most JRPGs where the 1st town costs 5 gold and the second costs 10 gold and so on, increasing cost arbitrarily with story progression. Make it cost a reasonable price per party member, balancing the benefits of larger parties. Introduce damage to gear which decreases combat effectiveness and increases maintenance cost.
Combined with finite resources in the world of NPCs and you may end up with a survival RPG :)
When there's no government to print money, it boils down to a fixed amount of e.g. gold that was mined until the game began, and continues to be mined as the game goes on. Like X gold/day from a mining facility that gets distributed between settlements and vendors. Sounds complicated, but can boil down to the amount of X gold being divided among the N settlements and then the Z vendors for a start:
That makes "ass-pricing" (Jason Fried) of items difficult. The price of apple, potion, sword, magic capes -- a round number for each item like 5g, 50g, 500g, 2500g in yer good ole JRPG won't do. You'd have to test prices a lot to see how players stop starving to death on day 4.
Drowning in money is easier than having a somewhat realistic simulation of being a poor peasant :)