Sure, but the flip side of this coin is that not everyone is into guns and just because someone doesn't want Grandpa's war rifle in the house doesn't mean they should get fleeced by some asshole who tells them that an all matching K98k is worth $300.
I've been in that situation before, helping family figure out what a deceased relative's collection is worth. Heck just last year my dead (for 4 years now) uncle's wife found four Russian SKSs in the attic. Basically "new in box" in the sense of in all the paper and the boxes that they came in from Century in the 90s/00s. He just tucked them away. She was a bit surprised when I told her that all told she was sitting on a couple thousand dollars, more than one person had implied they were basically garbage and offered to do her a favor and give her a few hundred. Don't even get me started on the Weatherby's that walked out the door with a cousin and into a pawn shop where he got pennies on the dollar.
People don't deserve to get robbed, even if they don't appreciate the guns the way we do.
edit: heck, if nothing else knowing it's valuable sometimes keeps them from handing them off to the local PD for disposal.