Nope, they aren't mid range. They are high end being sold for the right prices. 5850 and 6900 were heavily discounted, they were high end but cheap. These new cards are high. If they can be overclocked so high that the assured performance increase is 50%+ compared to previous flagship when comparing both overclocked, then they are high end and not even performance class
An Oced 7970 is about 50-80% faster than an Oced 6970, on an average 60-70%. It blows away 6950 cf as a setup, where fps is just a part and not the whole, is surprisingly close to a 6990 or 6970 cf within 10-20% performance in most cases once overclocked, and is far smoother because of this and a much better package at a lower price than 6990 or 6970 cf although it is an overall better solution with 90% of the performance and often even faster in fps terms
The gtx 680 oc is about 40-50% faster than a gtx 580 oc and sometimes even faster and it trades blows with a 590 making ven an overclocked 590 pointless.
And these cards are cheaper than these dual gpu cards
And from jan 2012 for at least another 8-10 months there won't be any better single card and amd won't release another big upgrade this year. Nearing q4 nvidia will release a card which will be nvidias main card or near main card for whole of 2013 and it will be just 20-25% faster but will need to compete with 8970 not 7970.
I see no reason to complain. From radeon 9000 to x2900 high end cards were always $500+ and usually just 20-50% faster than the previous flagship.
9700 pro to 9800 pro
X1900 to x2900
Only rarely do 60%-100% better cards come and 7970 comes close to that because Oced 7970 is at least 60% faster than Oced 6970 and previously we didn't have such overclock able nor scalable cards, 7000 series is the first.
And as for pricing, you can't amd to undersell themselves for life. They are now charging what they are worth, previously they were charging less than their worth