It's also a 24-core, dual-socket (12-cores per socket). There's a couple left on ebay:
http://www.ebay.com/itm/HP-Z800-Workstation-2x-Xeon-x5670-2-...
The one downside of this box is that the power supply is totally proprietary to HP. Well, the motherboard too. So if one of those craps out, you're done, unless you can locate a spare cheaply.
It's also reeeeaaally heavy and draws a lot of power.
Wow. The price is quite good. Is there some website you bought this from? How many cores?
>>But a 24-core new workstation would be much more expensive
Tell me about it. I've been checking the prices of a dual 24 core workstation and it is around $7K.