EPC via Newegg offers the refurbished Apple Mac mini Intel Core i5 2.3GHz Desktop, model no. MC815LL/A, for $379.99 with free shipping. That's $70 off and the lowest total price we could find. It features an Intel Core i5-2415M 2.3GHz Sandy Bridge dual-core processor, 4GB RAM, 500GB hard drive, 802.11n wireless, Gigabit Ethernet, HDMI, Thunderbolt, and Mac OS X 10.10 (Yosemite). Deal ends June 11.
A 90-day warranty applies, although it's unclear who backs it.