The 700 you spent on the system was not for the gfx card, it was for everything that is in the system.
If you bought it from a place like BB, you are always going to get screwed up the arse if you want a machine that can play games. That is what ZipZoomFly, NewEgg, and the like are for.
If can't build your own system, then go to a small mom&pop shop that builds PC's and they will let you design one.
From what you have listed though, the 700 bucks were not that bad. You did have only a $70 video card in it, but the rest of the system is pretty reasonable. Most of what you paid for was brand name though.
If you tell me your budget, I can tell you what the best card to get is.
It will help a lot if you give us a list of the key components in your system though.
RAM size and speed:
CPU:
Mobo:
Power Supply brand and wattage:
