Should I save up for a 7770?

So I was thinking a while back to buy a 7770 but as christmas came my money went, now I have enough money (and a £25 amazon voucher!) to buy a 7750, I was thinking that I wouldn't even really need a 7770 and would be fine with the 7750, the games I currently play are Gmod (maxed on high settings 30+ constant fps) Orcs must die (40+ fps all low settings) and planetside 2 (17-18fps all lowest possible) and I want to get newer games also to a higher quality, I've never been a quality guy so for me playing games on medium (high possibly) is fine, is a 7750 a good choice? and if it is which model(£80 below)? (if you suggest, suggest on amazon please!)