Sadly,,, I think too many casual gun buyers look at buying a gun & thinking; "I can buy it for X and sell it for Y." In short,, looking at it as an investment instead of as something to enjoy.
But if you buy it for X and KEEP it,, enjoy it,, and then, if you go to sell it a few years later,, you will often find you will sell it for more than what you paid. And you got the joy of ownership & use.
That is,, as long as you buy quality firearms.
And,, if investing is a major concern,, LEARN WHAT PEOPLE CRAVE, then buy those models.
Often,, I see people say; "Ohh, I like that model,,,, I want one,, but I'm gonna wait until the newness goes away & buy one on sale, or for less money!" BUT,, often,, many of these desirable guns are purchased quickly,, but NOT kept in regular production or get discontinued. Then the demands rise & availability is very limited. And then the prices rise a lot and the tire kickers, bargain hunters, or whatever are left without.
Convertible Bearcats, .327 Blackhawks, Buckeye Specials, Hawkeye's to name a few come to mind. (Although the Hawkeyes were not a high demand item,, but limited in production.)
Prices? Why worry. Buy & enjoy. But buy quality, buy what is desirable, and if you wish to sell, you will discover you will have enjoyed something AND often sell for much more than what you paid. Inflation or investment options are a wicked witch.