Really Tom, you should make cost/performance ratio a standard benchmark for your CPU studies. It doesn't matter that costs change daily, just make the cost/performance ratio accurate as of the date of publication.
If you were really clever, you would construct a database that updated its prices automatically for CPU's and produced a graph showing the best cost performance ratio of CPU's with real time data.
Why make your readers have to try and look up prices to see where the best bang for their buck is? You are telling us what CPU's perform..but what we really want to know is cost/performance ratio!
Moreover, you will be able to clearly illustrate AMD's dominance in this essential benchmark...and maybe even pressure intel to lower prices.