My character in our game has access to $3 million that was put in his name by some nasty people that are framing him for a murder. If he ever gets stupid enough to try to get the money, I guess this will become an issue for me. I wouldn't expect much in the way of rules changes though. I would think I'd have an aspect like "$3 million in magically marked bills" or something that could be invoked or compelled when those funds are important to the scene. But the biggest change would be that buying things would generally not be an issue that went to dice, since I had the cash. The focus would shift to things that were still meaty, like the consequences of buying the things I bought, or the complications of having that cash, etc.