Specialized Roubaix Di2 2017? Virtually everything has been renewed, replaced or upgraded? How much should I ask for it?

54cm frame. The original wheels now refitted only 18 months ridden. Future shock 1.5 upgrade. Di2 has new battery and RD. Hope calipers, discs and bottom bracket. New crankset. Cassette and chain in good shape. New handlebars and tape.