I recently played Pool of Radiance (the old one, from 1988), and gold had weight in that game. And it was pretty annoying. I was constantly weighed down by money through most of the second half of the game.
If money is to have weight, we definetely need some kind of storage for it. Like a bank, or a chest at home, or something like that. Otherwise, I think it will cause more frustration than anything else.