Burning Wheel has an interesting approach to wealth. You do not really have "money". You instead have a Resources stat, which you roll for skill tests to gather

Burning Wheel has an interesting approach to wealth. You do not really have "money". You instead have a Resources stat, which you roll for skill tests to gather resources to pay for things. As it is roughly feudal that makes more sense. You can get "cash" but that is used as additional dice to your resources rolls (and is used up on the test). And you can further abstract certain things as "funds" which act as a bonus to resources, ie your estate is a 3d fund which can be depleted.