New in box??!!? You'd be a fool not to take it. Even if it is slightly used! You will never find a better deal. I personally like the looks of a blued gun better. So many people are very paranoid about it rusting and what not, but from what I've seen, as long as you take care of it faithfully, you should never have a problem.
I am getting a GP100 6" blued this week. It is brand new and I'm paying $330 for it, which I thought was very good! My 4" GP100 is Target Gray (low glare stainless) and I paid $320 for it new. So yeah, you better snag that puppy!