MegaMacs offers the Apple PowerMac G5 Dual 2.5GHz Desktop , model no. M9457LL/A, for $319.99. With around $41 for shipping, that's $80 under our May mention and the lowest total price we could find for this system with 1GB RAM. Features include dual PowerPC G5 2.5GHz processors, 1GB RAM, 160GB hard drive, 8x SuperDrive, and more. Deal ends October 26 at 1 pm ET.

Of note, an OS is installed on this system, but it's unclear which OS.