Source for your claim about 6990 vs 7970 GHz?
I can provide numbers, can you?
http://www.techspot.com/review/546-amd-radeon-hd-7970-ghz-edition/
And now AFTER I've mentioned it, you say that fps isn't the only relevant performance metric...nice thinking for yourself there, buddy.
You still neglect the 28nm vs 40nm argument.
The 7970 (non GHz) was $549 at release, so yes, it WAS expensive. Do you know the price of the 780? Please post a link. "It's new" is a stupid non-argument. Wafer prices for 28nm in the beginning of 2012 were very high:
http://www.extremetech.com/computin...y-with-tsmc-claims-22nm-essentially-worthless
Just because TMSC claims they're ahead of schedule doesn't mean anything. First, they could exaggerate, second it says nothing about mass production and its volume and most importantly about price. Don't be so naive.
And since you seem to have so much information, please tell us: When will the 800 series appear and how much will it cost? And on what process node will the HD8000 series be manufactures (and I don't mean the OEM stutt, I mean the real successor) and how much will that cost? Will you cry foul, too, when that is only 20% faster?