I have to wonder about this last part of your post though. If this were true, no antiques would have currency after the generation that grew up with them dies off. We know that's not true.
I didn't say they'd be valueless, but part of the cache and thus the market definitely has to do with things like "birth year basses" and things like. When you take those out of the equation (because no one who was around then is around any more) you by definition take a lot of pressure off demand. Since supply will likely stay about the same that means prices will go down or at least stop appreciating. They may go up again, but I imagine it will be far out in the future, when anyone investing now will probably be dead. Even if your intent is to invest for your kids/grandkids/greatgrandkids, there are so many unknown variables that that's a fool's errand. You don't know what the market will do after your dead, you don't know if your kids or grandkids might sell the thing off too soon, or toss it, or destroy it, or what have you. So if you want to buy an instrument, it should be because you really like it as an instrument and want to use it as such. Any money to be made on it down the road is a bonus and should not be counted on. Still, if you always try to buy at below or at least AT market (and never above if you can help it), you have that cushion so you won't end up holding the bag if something DOES depreciate more than expected. But even if it does, I look at that like a rental fee. So you buy at $1000, keep for 10 years and then sell at $500. That works out to $4 a month to rent (whatever). Not bad at all (less than your Netflix account). Of course if you can buy for $750 and sell for $750, then you had it for free and can use that $4/month on something else.
Do you own anything that you keep just because you like having it around?
Everything I own is because I like having it around. But I don't let myself get too hung up on fantasy quests and I pay attention to good opportunities. So while I might not always end up with precisely the thing I want (like I really want a Rivera 55-Twelve combo, but I ended up with a VHT Pitbull 50 CL because I found a great deal on one in great shape, which is also a killer amp in the same vein and form factor). Since overall that tends to save me money, it allows me to have more than I might have otherwise (which lets face it, ultimately we're all on a limited budget). In this case, a Rivera is probably cheaper than the VHT, but that just means if I want to switch, I can get what I paid out of the VHT and get the Rivera instead. I haven't lost anything by going in a slightly different direction. Point being, if you stay flexible and don't get too hung up on details, your money will take you farther, faster. I bought a Hartke bass rig as an interim setup, not because it was the best thing ever but because it was SO cheap I couldn't pass it up (and I did like it and fit my needs). I sold it within a year and nearly doubled my money selling at market prices. Nothing at all "collectible" about 10-20 year old heavy Hartke bass stuff, but I was "smart" enough to identify a good deal and jump on it when it presented itself. Because of that I made money on it and subsidized other better gear (also bought at opportune prices). I may be an anomoly because I'm a multi instrumentalist and I'm making deals across a wide variety of stuff. And it takes work because you have to watch the "market" (ie CL, ebay, reverb, etc...) every day or at least every week to know what's out there and how much people are generally paying for it so you can strike while the iron's hot. But at the end of the day, I still only buy stuff I think I'll use because I could still end up holding the bag despite making a seemingly good choice (and stuff DEFINITELY takes time to flip anyway). If you do it right, you can eventually become a de facto gear store. and subsidize a much bigger gear collection than you might otherwise have.
. It's not about your personal feelings about it unless you're the one making the purchase. If you can't really figure out the goalposts on collectability keep saying bright stuff. It's a staple.
