All Smith & Wesson revolvers are fired before they leave the factory. I’m not aware of any “unfired” but I guess there could be.
Collectors that don’t shoot their guns will pay extra for a gun in collectable condition with the box. I’m a collector that shoots my guns. I might give extra consideration for a gun with the box, but not much.

Just like with cars, there are varying levels of collectors, level of conditions, and knowledge of buyers. I’ve collected Smith & Wesson Handguns for over 50 years. But I’d never try to buy a Registered Magnum, I just don’t know enough to get into that game.