I would guess it would depend on what "nice" and "expensive" means.
My deer rifle is nice, and the scope mounted on it is expensive. I looked at this rifle, which is left handed, at gun shows at least seven times. (probably for two years)
The vendor who knew me finally said, why don't you buy the rifle already, you look at it every gun show. I said why don't you come off your price, you lug it around to every gun show, besides I don't want the scope you have mounted on it. He asked what I would pay, less the scope. Needless to say, since I now own that rifle, we had a meeting of minds.
It now is companion to an expensive scope. Another time I bought a rifle from a guy I knew to be the original owner who was in a bind. A 2 year old, Rem 700 topped with a VX2 leupold for $175. All I wanted was the scope. (not what I consider expensive) I offered the rifle to a friend for $100 less the scope. He bought it and I let him take it with the Scope which I would remove later. After shooting it he wanted to keep the scope as well. I told him it would cost me $200 to replace it used, if he wanted to keep it he would have to cough up another $200. He still got a great deal. The moral of the storys is you should probably offer it both with or without the scope.