I think you'd like how Exalted handles money. (Note: I'm talking about second edition here; I never got familiar with third edition.)

In Exalted, wealth is represented by a Background called Resources. Backgrounds are essentially stats that represent useful things your characters has in a general sense like wealth, fame, contacts, or a mentor. They go from zero to five.

Resources is a vague representation of wealth. At Reduces 1 you're one meal away from total poverty. At Resources 5 you have something that passively generates substantial amounts of money for your character, whether that's ownership of a lot of land or an army of accountants maintaining your investment portfolio. Whatever is is, it works without you having to deal with it.

In terms of game mechanics it's easy to use: Prices are expressed as Resource scores. If you want to buy something you just compare your score to the item's.

• If yours is higher, you just get the item as the price doesn't affect your wealth significantly.
• If both scores are the same you get the item but have to reduce your Resources by one. This represents you having to liquidate a large amount of your assets to cover the price.
• If your Resources score is lower than that of the item, you can't afford it.

It's a nice system for a game that doesn't want resource management to get in the way of epic adventure.