Try to grab a 4850. The GTS 250 is a rebranded 9800 gtx or + forget which. The GTS 512 will get you similar performance to an 8800GTX btw :/ so it is a decent step up from a 320.
Originally Posted by Drakan290
Guys, the 4830 crushes the 8800/9800.
The GTS250 will beat the 4830, but tie the 4850 (GTS250 = 9800GTX+, GTS240 = 8800/9800)
Get a 4830, you'll be impressed, I guarantee it.
Read these two articles for some more info: