Re: Processor prices tend to rise exponentially with performance so I would think that you'd get more bang for the buck going to multiple processors before scaling a DC by 8%.
This is not a price/performance argument. Regardless of how much performance a new CPU offers, demand for that CPU is inversely proportional with the price. $1000 CPUs don't sell more than a couple thousand per quarter - if that.
Re I see premium bins in other areas that AMD is taking advantage of. The 81.5 Watt 3700+ is $319 at Newegg. The 62 Watt version is over $500. That's pretty decent money for stuff that's nowhere near the top-of-the line.
And if these were the most popular sku, AMD's ASPs would be a lot higher than $100. In fact, they'd be about 3x higher. The fact that they are not should tell you that even 3700+ processors aren't the midpoint in processor sales, but rather still a high end sku. I'm guessing that overall, probably about half of AMD's processor sales are Semprons, while only a small fraction are at 2.4GHz and above, and an even smaller fraction are dual core.