So I just recently purchased a used but functional MSI Twin Frozr 7970 for $180. I think I got a good deal on it but I'm wondering how good? I currently have a 570 GTX so I know its good upgrade. But did I get a good enough deal that I should look to resell and go with something else like a 760 GTX or 770 GTX? I don't have a lot of money to spend but the 570GTX is getting long in the tooth.