No simple answer - many, many of the used guns I see are better than - worth more - than many new models.
The two guys I know that buy such amounts from an estate or from a person getting rid of a collection have stored a lot of value knowledge in their heads. They have a way of arriving at a solid estimate of what the whole kaboodle is worth and offering cash at about 50% of what they think they can get in return. They can go upward with the offer if necessary and they feel it is worthwhile, but their willingness to buy everything - down to the last sling or gun bag - makes their approach more attractive to the seller.
