If the frame is good; the frame alone could sell for 3 to 5; complete bike , rideable, good shape, THAT model, 4 would be a low price, I've seen them hit well over 5.
DO make sure that the frame is good, not bent. The fork's condition is a place of focus. The bars, other incidentals detract from the complete bike value. If it's not at all bent, if it's not impossibly scraped, dinged etc, with any semblance of parts; crank, brakes, drive train... paying less than 450 would be a bargain. Bianchis command more than they're "worth'. Camp. D. Ms are up there in the order. Enough to know for now. Make sure that name appears on the bike; year, exact parts etc. goes from there.