Yeah, I can get onboard with that. PC parts are generally pretty cheap right now. A new mobo, mid-range Core2Duo, and decent PCIx card (8800GT/9600GT) won't set you back much at all. Like I posted about earlier, I just bought a 9600 GT for $100, and the price of that has gone down a tiny bit (on sale) since. Beyond that, the 8800GT has dropped into the exact same price range, so that might be a better option.
If you can transfer your HDD, drives, and PSU/Case over as well, you're really balling. Ram costs pretty much nothing, especially in the kits they sell for dual chan. motherboards these days, and you can always upgrade your HDD for more storage whenever you need it for pretty cheap.