I also agree with juin, but I disagree with P4Man about his comments for the Athlon FXs. Athlon FX-51 is this expensive because it is (practically) an Opteron 1xx. AMD never intended to sell high volumes of this chip, neither wanted to hurt the sales of 1xx Opterons. They only released it back in September, at A64's official launch, because releasing just the S754 A64 and saying that the "power" A64 will only be ready in Q2 2004 would be much more harmful to them, since the A64 was already a couple of years late.
Anyway, I believe that we will see lower prices on FXs when they are released on S939, along with cheaper mobos (it has something to do with the layer design the Opteron requires, I don't remember exactly). The only reason that I don't see prices coming too much down though, is because I don't see a 2.4GHz A64 FX have any real competition from Intel, so unless faster Prescotts are released to threaten the FX-53, then AMD will have no serious reason to bring the price down.
And don't anybody here mention the P4EE because I hardly considered a >$1000 CPU, a desktop product. IMO, only S*P*E*C*I*F*I*C people are justified to get this CPU, others who get it just for gaming for example or for bragging rights, are simply stupid.