Hmm... Now I don't now what you paied for your computer, but are you a gamer type who wants the state of the art machine, og do you only need it for normaly internet surf or so?
If you just need to check emails and surf on the internet I would say it's best to just buy a new one.
If it's allready a toptuned pc, you have bought for 15.000 ,- Or so when just fix it....
It's your decesion, but the computers today are so cheap so i would buy a new one if I where you