The really nice stuff will hold its value provided its condition is, basically, to use a term I've never seen applied to a firearm, immaculate. But the days of passing off a bunch of guns accumulated and used over a lifetime as a 'collection of fine firearms' are gone (that last observation is my Dad's, when I was helping him get rid of 30-35 guns when he and my Mom moved into assisted living a few years ago, he was a clear headed pragmatist).
I don't think the Second Amendment has much to do with it. Or social attitudes, really. The move to non-toxic ammo drives down the value of firearms that have been shot, of course. A flood of fine doubles out of Europe and the UK increases supply at the very time when demand is receding due to demographics in this country, and that should tend to put a thumb down on prices. So be it. Why should anyone make money off their hobby?
The market for classic cars or fine watches may offer a pretty good example of what's to come. Older cars tend to be attractive to guys who couldn't afford them in their youth and now can, so they pour money into restorations and concours-quality rebuilts and for a few years the market goes crazy, then it stabilizes and, as that generation ages out of the accumulation phase and into the disposal phase, the prices collapse. While a few museum worthy classics find their way into those collections, the market is awash in really nice 'summer drivers' and such, for which there is no market. The market for expensive watches is also, from what I read, in some kind of tailspin. So be it.
