CompUSA offers the factory-refurbished Gateway GT5670 AMD Phenom Triple Core 2.1GHz Desktop PC for $339.99. With around $22 for shipping, it's $90 under the lowest total price we could find for for a new, factory-sealed unit. It features an AMD Phenom 8400 2.1GHz triple-core processor, 3GB PC2-5300 RAM, 320GB Serial ATA 3.0Gb/s hard drive, dual layer DVD burner with LabelFlash, flash card reader, and Windows Vista Home Premium. This system is backed by a 3-month Gateway warranty.

Of note, pay via PayPal for $20 cash back, making it $319.99. The PayPal discount will be credited to your account within six to eight weeks after purchase.