I know what you mean, when I do spend its usually for Spell Tomes like Paralysis, Detect Dead, and Detect Life.
I mean, I horde everything not nailed down. I just have no need to accumulate any amount of gold. Now, if we were to consider the net worth from total assets then I'd imagine it would get quite large.
TBH it is best to actually sell off stuff all along, to help with savefile bloat from massive amounts of stored gear and various loot.
But alas, I somehow think I may actually have a need for those 200 Iron Daggers and 75 pairs of Ragged Robes for late game.