So you want to get the A64 thing going but want to do it cheaply.  Will that A64 3000+ do what you need?  Take a look at this article from Hexus as they do the benchmarks with the 3000+ vrs the other A64’s as well as the P4 3.0, 3.2, 3.4 competition.
“The Athlon 64 Model 3000+ was a much-needed CPU in AMD’s
performance lineup. All we now ask for is a 1.8GHz 512kb L2 cache
version priced at around £140. That would cover Intel’s present
Prescott and Northwood range admirably. We’ve only evaluated the
32-bit side of the processor. Its attractiveness will be further
boosted when Windows XP, in particular, launches the final 64-bit
version shortly…”