Update
It's been some time since I've looked on craigslist for much of anything. But I'm glad today I did. For about $350 I purchased a 42U Sun Microsystems server rack and two Mac Xserve servers. How could I not go wrong!
The server rack Brand new is easily $1,500 to $2,000 and the Mac servers used any where between $100 and $500.
The two Xserve servers are a little different I guess...
Xserve G5 (pcitured bellow)
pcu: unknown
ram: 8gb
2 hot swap bays
needs a new PSU and HDD's
Xserve #2
pcu: 2x 2 Ghz Dual-Core Intel Xeon
ram: 16gb
2 hard drives with hot swap
running OS X
and finally got the rack in the basement!
So overall it was a good deal, and if I don't use the Xserve servers I'll probably part them out. But to get the rack at the price I did was well worth the investment even though I planned on waiting.