Groupon offers the refurbished Apple iMac Intel Core i5 2.7GHz 21.5" Desktop for $679.99 with free shipping. That's the lowest price we've seen for this late-2012 model in any condition, and the best deal we could find for a refurb today by $75. Features include an Intel Core i55-3335S 2.7GHz quad-core processor, 21.5" 1920x1080 LED-backlit display, 8GB RAM, 1TB hard drive, NVIDIA GeForce GT 640M 512MB video card, AirPort Extreme (802.11n), Bluetooth 4.0, Gigabit Ethernet, two Thunderbolt ports, FaceTime HD camera, and macOS Sierra. Deal ends July 18.

Note: A 90-day warranty applies, but it's unclear who backs it.