B&H Photo-Video offers the Apple Mac mini Intel Core i5 2.5GHz Desktop, model no. MC816LL/A, for $649.99 with free shipping. That’s $49 under our October mention of a refurb (this one is new) and the lowest total price we could find for a new one by $113. It features an Intel Core i5-2520M 2.5GHz Sandy Bridge dual-core processor, 4GB RAM, 500GB hard drive, AMD Radeon HD 6630M 256MB graphics, 802.11n wireless, Gigabit Ethernet, Bluetooth 4.0, SDXC card slot, and Thunderbolt.
Of note, this unit will ship with either OS X 10.7 Lion or 10.8 Mountain Lion.