I'm looking at a 2008 Mac Pro I found off my local Craigslist. The specs are: 8-core (2 quad cores) 2.8GHz Intel Xeon 5300 series 4GB RAM 1TB HDD DL SuperDrive Nvidia 8800 GT 512MB VRAM It's listed for $600 and includes pre-installed OS X and the power cable. The seller (an electronics store) has refurbished it, so it's in grade A condition with a 30-day warranty. What do you think of the price? Is it average, good, great, bad, etc.? Also, how well will it perform in comparison to the iMac in my sig? Your help is much appreciated.