I like the idea I've seen floated around (maybe originated by Jeff Rients?) that you only gain the XP for treasure value by spending it carousing. Basically, it doesn't matter how much loot you liberated by invading the Benevolent Temple of the Kobold Great Mother and slaughtering the holy innocents there, nobody's going to know about it unless you blow some cash at the Black Boar and tell people about your exploits!
And people knowing about it is what makes you better at stabbing, sneaking, and casting spells?
I mean, that's totally a metaphysics you can work with, but it means hiring bards to sing your praises is a way to gain mechanical power....