They wouldn't do that, at least not in any significant amount... That kind of action is asking for some serious class action lawsuits.
Fyi, there are $100 nVidia cards that suck right now too, the problem isn't that the card was more expensive than it should have been, the problem is you didn't do your research. Both camps have always had their crappy cards sell for 3-4x their worth, just for the uninformed people to purchase.
I'd bet if you looked hard enough you could find a 9600gt for over $200.