To be completly honest you don't have to pay a cent for a G5. All you need to do is spend some time on the phone calling 3rd party mac resellers and repair shops. When a fan or powersupply dies they often just give the customers new assemblies with their old mainboard in it and chuck the leftover case. yes chuck as in throw out, 86, send to the trash can. Thats how I got mine. I jerryrigged my g3 in it and I plan on posting it for the mod contest this weekend.
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Mobile-2.2Ghtz Core 2 Macbook, 4GB ram, 160GB HDD
Server-Dual 1.42 MDD G4, 1GB ram, 4 random hard drives.
PC-C2D 2.4Ghtz, Asus Commando, 2Gb ram, 3 hdd's in raid 5, 8800GTS.