So reduce the money you get from caravans, fiefs, and workshops?
Perhaps, but I'd rather see town upgrades that cost upwards of 50k. Perhaps even upwards of 100k. It would be better for the game if the devs created something for us to do with all the money rather than just nerfing it.
Either way, equipment needs to be a lot cheaper. They're basically vanity items in the grand scheme of things. A player's personal input on combat is negligible to the outcome in all but the smallest battles.
And if you nerf equipment prices you also nerf battle-loot, which is a much bigger contributor to all the late-game wealth players have than enterprises. It'll balance eachother out.