datavis via Buy.com offers the Apple iMac Intel Core i5 2.7GHz 27″ Desktop, model no. MC813LL/A, for $1,139.99 with free shipping. That’s the lowest total price we’ve seen for this configuration, new or refurbished, by $219. (We listed a refurbished model from Apple for $1,359 shipped earlier this week.) This mid-2011 model features an Intel Core i5 2.7GHz “Sandy Bridge” quad-core processor, 27″ 2560×1440 widescreen LED-backlit glass display, 4GB RAM, 1TB 7200 rpm hard drive, 8x SuperDrive, Radeon HD 6770M 512MB graphics, AirPort Extreme (802.11n), two Thunderbolt ports, FaceTime HD camera, Bluetooth 2.1+EDR, Gigabit Ethernet, and OS X Lion.

Of note, this system is eligible for a free upgrade to Mountain Lion.