The Apple Store offers its factory-refurbished Apple Mac mini Intel Core i5 2.3GHz Desktop, model no. MC815LL/A, for $519 with free shipping. (It's the top model.) That's $46 under the lowest total price we could find for a new unit. Sales tax is added where applicable. It features an Intel Core i5-2415M 2.3GHz Sandy Bridge dual-core processor, 2GB RAM, 500GB 5400 rpm hard drive, 802.11n wireless, Gigabit Ethernet, Bluetooth 4.0, SDXC card slot, Thunderbolt, and Mac OS X 10.7 Lion. A 1-year Apple warranty applies, the same as new systems.