You have to be careful about purchasing those not new and OEM. I have seen them sold as "working" but end up having the "intermittent network connectivity" problem that seems to be plaguing the older VPs and VPi machines.
I'd buy it OEM. I'm sure that you'll be able to find a dealer that will sell you one. It's about $2k new. Unless a current certified tech installs it, you won't get a warranty with it (90 days on parts).
You might be able to find a parts machine... but then again, it's a crap shoot.
~E