Ending today, Expercom offers the Apple Mac Pro Intel Xenon 6-Core 3.33GHz Desktop PC (no monitor), model no. Z0LF, for $3,899 plus $27.50 for shipping. That's $100 off and tied with last week's mention as the lowest total price we could find for this configuration. It features an Intel Xenon Westmere 3.33GHz six-core processor, 12GB RAM, 1TB 7200 rpm hard drive, AMD Radeon HD 5870 1GB graphics, 8x SuperDrive, and more.

Note that no operating system is specified.