Why does it have to be a geforce card? I just upgraded the 5450 in my Dell to a 7750 for about $60 on Black Friday. Black ops 2 plays at near max with 60FPS at 1280x1024. I would have gotten a 7770 but they were sold out. I'm not sure what the geforce compatible priced cards though.
And don't bump posts 30 mins apart.