I do think the point with increasing gold reserves makes sense. It is of course connected closely with the idea of less nobles. So as nobles decrease, the gold per noble increases.
For instance, on average a noble on Atamara currently has about 1,600 gold. That is utterly insane. That is the current outstanding gold amount.
How will that ever get spent?
The idea of implementing a system whereby you can spend tens of thousands of gold is a good one I can certainly support.
Alternatively, you could inflate prices of everything. It would probably increase game balance somewhat.