MegaMacs offers the refurbished Apple Mac Pro Xeon Quad-Core 2.8GHz Workstation, model no. MA970LL/A, for $599.99 plus $2 for shipping. That's tied with our mention from a week ago as the best price we've seen for this workstation. It features an Intel Xeon 5300 Series 2.8GHz quad-core processor, 6GB RAM, 500GB hard drive, NVIDIA 8800 GT 512MB graphics, and SuperDrive. Deal ends September 4 at 3:30pm ET.

Of note, an OS is installed on this system, but it's unclear which version. A 30-day MegaMacs warranty applies.