Well, assuming I run another game with more standard item practices in it (I'm very ham fisted in the one I'm currently DMing), I have this plan. First, there's not all that much cash around. I mean, sure there's cash, but not the situation were each member of the party is hauling around 10 pounds of coinage with mighty jingle jangling. There'd be a lot of copper, some silver, a little gold. I'd consider the wealth guidelines as a sort of invisible score. See, the large quantity of money that a magic item costs isn't really what it's about, the cost associated with the item represents instead the sort of influence it can pull in.
It'd work via interactinons with the rich and powerful. Say our fighter has his trusty longsword, bitey (+1 keen). Now, after their crawl into a deep dark dungeon, he gets a new sword, burney (+2, flaming burst). So, he presents the sword to his liege saying, "Bitey has served me well, protecting my life with its fierce edge. I present it to you in the hopes you may find him a worthy successor." Behind the scene, the fighter's score just goes up by bitey's sale price. Now the king is really impressed by this, which is the third gift he's recieved. So, he gets up and says "This shield was carried by my father's champion into battle. Carry it with honor." And the item's cost is deducted from his score. Now, later on fighter really wants some boots of springing and striding, so he talks to the king, who is, after all, really impressed with fighter's work. The king puts in a good word in with the wizard on forgotten keep, and the player's score (or at least a part of it) is transferred to be used as invisible spending cash at the wizard's 'store'.
Now, let's say fighter's used up all of his score, but after a recent dungeon raid, has a few items that are unclaimed by the party. He gives one or two as gifts to the king as he makes his audience, and asks "Magesty, I was hoping that you could help me. My family has been displaced, and I need your favor to find them a new home." The king is so impressed that he sets them up with as good of a household as those items' worth tranferred into gold can buy.
The downside of all of this assumes that there are some large, powerful entities (guilds, kings, churches, Wizrds, planar creatures) that the party is willing to work with, accept gifts, and can give stuff back.
On the other hand, it gives me a good way to have a favor 'meter', and even better, I can still have ridiculously well equipped adventurers who can't afford a roof over their heads and are living on favors, and for whom an easy guard job that offers gold is still enticing.