The Tech Report compares the latest processors in terms of overall performance per dollar and power efficiency, you can check it out over here.
As you might have already seen, the value section of our grand Athlon II vs. Core i3 showdown article includes performance-per-dollar graphs based on whole system prices. We began including these numbers some time ago at the behest of a readers who rightfully feel that, if they need to buy a whole PC to begin with, then processor pricing is only part of the equation. For example, if processor A costs $200 and only performs 50% better than processor B, which is priced at $100, then the prospect of paying double for 50% extra performance may not seem that worthwhile. In a $900 system, however, paying an extra $100 for 50% of extra performance suddenly becomes far more enticing.