If you are reasonably mechanically proficient, $2799.95 seems about right.
http://www.bikesdirect.com/products/...ltegra_di2.htm
I would be very surprised if you could walk out the door of your LBS with a CF frame, Di2, Ksyrium wheels, etc. for less than $6000.
I bought a (much less expensive) BD bike, and was delighted. I might be more hesitant to buy cutting edge technology that way. On the other hand, Di2 seems like it's more inherently self-adjusting than mechanical shifters and derailleurs.
Did you maintain your own motorcycles?