However, we may be looking at a long term lowering of prices on many currently collectible guns, especially revolvers, bolt guns, hunting rifles and shotguns. The younger generations don't have the same tastes, seem more interested in ARs and semi-autos pistols that they encounter through video games and movies, and they are less and likely to be hunters. I can't see a young kid wanting a vintage model 94 when he doesn't hunt, doesn't watch westerns, and is four generations from the second world war.
The other thing I see collecting possibly becoming is a limited niche market of only the rarest guns. A collector dies and his kids inherit the guns, but they don't really want them. So they sell them. His one super rare signature end up in the hands of a very wealthy elite collector who can afford several thousands of dollars on one piece. However, the more common, run of the mill Mausers get sent to the market. That increases supply and creates surplus, and the buyers out there are interested more in ARs, and don't have much interest in what they see as a beat-up, old relic. That means decreased demand, and all of this drives prices downward.