Apple offers its refurbished Apple iMac Intel Core i5 1.6GHz 21.5" Desktop for $849 with free shipping. That's $51 below our November mention of a new unit and the lowest price we've seen. (It's also $140 under the best deal now for a new unit.) It features an Intel Core i5 1.6GHz dual-core processor, 21.5" 1920x1080 LCD, 8GB RAM, 1TB hard drive, and Mac OS X 10.11 (El Capitan).
Note: A 1-year Apple warranty applies.