That's a screaming good deal even with no-name wheels, FSA crank and Tektro brakes! I think the Orion has been discontinued, but it would make a great racing bike. Upgrade the crankset and brakes for $300 and $2100 for a full Ultegra Di2 carbon bike is about as good as it's going to get.
The last 'deal' price point I saw on partial Ultegra Di2 Carbon bikes was in the $2100 range, so $1800 is killer IMO. Performance is still pegged at $3300 for the Fuji SL 2.1. That makes the Ridley smell even better.
It would not surprise me if Ribble was buying from FLYXXII. Generic carbon cheap sacrificial frames are just what the doctor ordered!