It’s like the general economy in micro , while people have confidence in the value of these things, the value will hold up , but if the value in a guitar is that it was a present from grandad, mum and dad or wife for instance , or it was one that has particular band or gig memories. then keeping it on a stand in the corner of the room is value enough.
Nail it to a wall as a decoration or as a cherished memory, fine by me, I think an emotional attachment to an instrument is easily as important as its monetary value