Honestly depends what you are doing with it. If it's for gaming it's going to need some changes. If it's for everyday use and stuff it's a good deal.
Since your on here the answer to that is probably gaming. For the money still not a bad deal just do what you said and toss in a new card either the 8800GT or new 9800 GTX(I believe it's a shade under 300) should improve things greatly.