As an Old School DM I'm big into "other treasure" and "other rewards".I don't know, I can think of plenty of rewards you can find that aren't straight cash.
"There's different kinds of treasure mate."
First, I use the Ye Old Silver Economy, so gold is rare. And other then dragons, you won't find piles of gold anywhere.
I do pile on the other kinds of treasure. And I use spells as treasure.
And other rewards like a favor, a title or such too.