Capt. Horatio Slappy !!
Not sure which Benchmarks you are looking at? From what I see, an Athlon64 running 1Ghz slower than the so called Extreme Edition, runs every bit as fast with software that is not even 64bit yet and on drivers that have not had a chance to mature.
Athlon64 3400+: Part 2
Take Care,
Richard
P.S. Wee Weasley Welshman, sorry we have gone O.T. For the money I still think that you should go with an AthlonXP for now. It is more than fast enough and will give you great value over its life. When you decide to go for it. I will do what I can to help you acquire the parts on this end of the pond.