FPS is what you probably mean.
You don't really need a expensive card to play crossfire, what you probably really need might be a processor.
Now a days I see many problems with pc is that their cpu can't keep up with the game it self.
The best I can say is to get a Dual core and probably a GTS 450, your price will be around 100$ (Depending if you need a new mobo)
If you got 200 spend then save it and make your own or buy a already built gaming pc.
I would save up for a pc like this: http://www.ebay.com/itm/INTEL-CORE-I...item35c145d605
or something similar.