MegaMacs offers the refurbished Apple iMac Intel Core 2 Duo 3.06GHz 21.5" Desktop, model no. MC413LL/A, for $599.99 with free shipping. That's tied with our refurb mention from three weeks ago as the best price we've seen for this model. (It's a current low by $49 for a used model.) This iMac features an Intel Core 2 Duo E7600 3.06GHz dual-core processor, 21.5" 1920x1080 (1080p) LCD, 4GB RAM, 1TB hard drive, SuperDrive, Bluetooth 2.1+EDR, AirPort Extreme, and OS X 10.9 Mavericks. Deal ends September 10.

A 90-day MegaMacs warranty applies.

Of note: Newegg offers it for the same price; however, it has OS X 10.6 Snow Leopard.