That's as a result of it adjusting the mix of processors between the eighth of November and Boxing Day, according to Planet3D Now.
Here's the English version of this text:
We would like to inform you that AMD will shortly implement a price move on some AMD processors. The new prices will be available for a limited period only, from Monday 8th November to Sunday 26th December 2004, and will affect the following model numbers:
AMD Athlon 64(tm) desktop processors for model numbers 3500+, 3400+, 3200+, 3000+ and 2800+ AMD Sempron(tm) desktop processors for model number 3100+ only.
For further information on pricing and availability, please contact our authorized distributors. Their contact details can be found at www.amd.com/EuroDistributors.