I buy things to enjoy using them but I do confess to having value appreciation in the back of my mind. My comparison of buying guns instead of CDs is that both will likely appreciate in time; CDs because of the interest earned and guns that are quality pieces will appreciate but even if they don't, I received the fun of using them instead of interest.
I believe Smith & Wessons to be good investment items because they seem to be the Harley-Davidsons of the firearms industry. Other manufacturers also make nice guns but S&W ownership is almost cult-like, much like the Harley crowd. That never hurts resale value.
Some of the guns I've purchased are worth more than I paid for them; some aren't. In S&Ws, I have a no-dash 617 and a 5" 629 Classic DX that are easily worth more than I paid for them. In Remingtons, I have a Model 700 "C"-grade that was made in Remington's Custom Shop in 1974 that I paid $500 for. Did I mention that it's also a 6mm? I had a twin to it in .270 that I sold for $1,500 five years ago. New ones like it START at $2,300 today.
The S&W 686 and 629 PowerPort guns could be collectable one day. Non-IL guns might be, too, if S&W never goes back to no-lock guns.
For the amateur, beer-pocketbook collector like me, there are guns like the Remington Model 700BDLs made between 1997 and 2001 that have scroll engraving on the receivers, Model 700BDLs with detachable box magazines (only available on blued SPS version today), stainless steel 700BDLs, 700LSSs (discontinued in 2008), Model Six pump rifles (only made for five years), the XP-100R bolt-action "handrifle" (only made in 1998, the last year of XP-100 production), single-shot, low-recoil Model 870 Competition Trap guns (only 5,300 were ever made and production ended over 10 years ago) and any Remington rifle in 6mm. With the exception of the XP-100R, 870 Comp and some 6mms, they don't bring a whole lot more than their still-produced equivalents do but have the potential to appreciate at a higher rate.
Along those lines, I have an unfluted 686-3, an unfired 686-3 PowerPort, a 629-5 PowerPort and the previously mentioned 617 and 629 DX. I have other S&Ws but those are the ones that stand the best chance of being considered unique some day.
Gun collecting is fun, especially if you shoot them. If your kids also appreciate fine guns and will enjoy them, too, then buying them is an even better idea.
Ed