$450-$500.
The scope will add little if any. Used glass is not worth much unless it's one of the big names (Leupold, Zeiss, Minox, Meopta & a few others). And if it's got high end glass, you usually come out better to sell the refle and scope separately.
Nice rifle though, and they do hold their value VERY well. I wish they didn't most times, 'cause I'm always buying them instead of selling them. You can get a short action Model 700 a lot cheape on the used market, but they just don't feel the same.