It's more like, the cheapest card isn't generally the most attractive to the buyer, at all, notice how(last I checked) the cheapest 680gtx, the OCUK branded one was the LAST to sell out, with other cards that were more expensive selling first. Even with no custom cooled cards at all people prefered going for what they perceive as a "big brand" over an OEM card.
With 7970's you're talking about reference vs oem vs pre overclocked vs custom cooled vs overclocked and custom cooled. So with almost no difference in 680gtx the cheapest soldout slower than more expensive ones with a vast difference in cost, cooling and clock speeds the 7970's cheapest card not selling out instantly somehow means the cards aren't selling.......... or more 555BUK talking crap?
As for deciding 10+ in stock means zero sales, more illogical nonsense, the only thing that is proof of, is how much supply AMD were able to establish and fairly quickly as well.
He's also ignoring the fact that other stores got plenty in, sold out, got plenty in, sold out, rinse repeat for the past two months and that little thing called the 7950, which is simply better value, as the 570gtx, 5850, 6950, 8800gt, etc, etc. The top end cards don't sell in huge volume, the top but one cards still aren't huge volume but usually pretty massive vs the top end card. It's both expected, normal and will absolutely happen with the 670gtx, that the top but one part will outsell its big brother many times over.
On Apple, not really sure what they're making at this point on 28nm, if they are making anything. The A5X afaik is still made on 45nm, but people were expecting it to be 28nm.... seems very possible Apple had a 28nm part ready to go but capacity just wasn't there from TSMC to go ahead with it so they launched a not quite great but decent enough 45nm variant of the design. Could they be building up stock of 28nm chips for phones and future tablets, sure, but with TSMC's capacity not increasing that fast they might have gone elsewhere.