Just by way of comparison...I picked up my all carbon Tarmac, an '08 Ultegra/105 mix for just under 800 just about zero miles on it. Owner bought it to do an MS150 and realized he didn't enjoy riding.
Deals like this are fairly common from what I've seen. He started at 1200 and no one responded.
Link to thread on the purchase
http://www.bikeforums.net/road-cycli...-question.html
picture of bike at next to last post