I have often wondered if some movie props were just another item, or if there was something special about them. I know with Star Wars items they are unique. When it comes to musical items I don’t believe the same thing to be true.
Musical items are probably mass purchased and used because they are not as expensive as things that need to be handmade. The guitar from Wayne’s World was probably available at any Fender Stratocaster guitar center.
I have watched Comic Book Men and they have gotten in some pretty unique things that were mass produced, but worth some money. I may try to take a vintage GI-Joe action figure to them to see what it is worth.