I hope you realize that you wasted a lot of money right? You could have gone with the 5830 @ 130 and still done way better or by waiting you could have received an even better deal. The only argument for getting the 6970 is because its going to be a part time mining rig part time gaming rig and its clear those wont be used for gaming.
I disagree, one thing I also check for is resale value. A 5770 is a good miner per cost, but you won't make anything back selling it. A 6970 will have awsome resale value. I sincerely hope that bitcoins really take off and I'll never sell my mining gear, but if I have to my 6950's will still sell at decent prices.