I'd give $500, maybe $550 if it's in absolutely perfect shape. If he thinks you're lowballing him, tell him to try to sell it to a gun dealer and see what he's offered. It may be nearly new, but it's still used and almost all new firearms lose significant value the instant the first round goes down the pipe. He should also understand that the scope isn't worth anything toward the value of the used rifle. All of the cheap China specials aren't worth crap for resale. If he had a Leupold, Zeiss, Nikon or other mid to high end scope on it it'd be worth more, but not with a Simmons. I'd offer him $500 cash-in-hand without the scope. If he wants to dicker, I'd go as high as $550. If he won't take $550, take your cash and go scour the local gun and pawn shops. I'd bet that sooner or later you'd find another similar Model 700 for $500 or less.

Mike