Hmm, odd. I've never noticed being "too rich" in games. Probably because it doesn't bother me if I have lots of unused cash lying around - not having anything to spend it on isn't really an issue. Probably because the games where you have "lots" of money? There isn't anything you need to buy anyway (after the first few levels) - you get everything useful from looting. Money's just a "score" you can use to trade brags with people. :shrug:
In my case a huge part of the fun of RPGs is trying to accumulate wealth and scrounging and saving up to buy that cool item that I really want.
If I ever reach a point where I'm so ridiculously wealthy that I can easily buy anything in the world, the game becomes a lot more boring for me, because there is no more point to accumulating wealth.
I usually play Oblivion, FO3 and FNV with mods that make all the prices about 5x more expensive. This way, even at higher levels, I still have to struggle to afford the coolest items.
And if I'm playing with survival mods that require eating, drinking frequently, then a lot of money is spent on food and drink. Oblivion spells end up being extremely expensive this way, so it is really fulfilling and rewarding to finally be able to afford a particular powerful spell.
At very low levels it is brutal and a huge challenge to earn money and survive, but this is kind of how I imagine it would be in the game world.
For example, on a heavily modded version of Oblivion, I've been playing for 350 hours and I'm still extremely poor. Spells cost thousands or even 10s of thousands of gold to purchase. If I was playing vanilla Oblivion after about 30 or 40 hours I would probably be rich and the game would become a lot more boring.