That is not a 1973, it is a MKV frame which means it is circa 1978ish like mine. The MKV frames are probably less desirable without the fastback seat stays, chrome and Cinelli sloping fork crown. I agree that the price is high for the condition, but it's not terrible. The saddle is probably not original, it should be a Brooks Professional. It's still a pretty nice looking bike, it could clean up really really well.