AMD

[John P. Myers]

So which are cheaper, the older 7xxx or their "R" clones?

Pretty much the same price +- $10. At least on Newegg the 280Xs seem to be $10 cheaper than the 7970GEs ($300 vs. $310). However if you're in the market for a used 7970GE, those can be found even cheaper, while there are no used 280Xs yet, so that could save some money

Edit
@Mumps: Nope, no die shrink. Same 28nm as before. Last i heard TSMC won't be making the new 20nm wafers in useful quantity until June, but i'm not sure how AMD will handle that. It's too soon to release a "next gen" model based on the new die shrink, and at the same time there's no way they'd throw away the chance to release a "next gen" based on the new die shrink. I see release delays in the future...

Unlike Nvidia, AMD did tweak the original 7000 series chips a little for use in the Rx series, and based on compute benchmarks from Anandtech, the 280X seems to be 1-5% faster (though usually closer to 1%).