Now, the "normal" Xeon 2 GHz/512K cache can be found easy for under $300 each, actually the 2.2 GHz probably can also. But, when you buy a Tier-1 manufacturer system the processors are 'way' more - probably for warranty purposes, etc.
I think HP may have dropped this line, but for comparison a somewhat similar Dell 530 workstation is ~$2,800 - but with newer features (IMHO)...