I have occasionally thought about this subject, but then I get sidetracked buying another gun that "I always wanted". I have an awful lot of guns. I have always thought that they were an investment, and they are, but my GF says that I never sell any of them. And of course she's right, but on the other hand, I have other investments that I haven't cashed in on, and in fact am still putting money in 403B, etc., which I hope to take out some day. I have two sons that like guns, and three grandchildren, and the GF, so there are folks to pass them down to, but probably they would not want all of them. I do have a database which includes approximate value, a history of each gun, whether it has any family significant family value (my service guns, for example, and ones that came to me from earlier generations), and this will be a help to my family in deciding what to keep, and what to expect to get if they sell.
But I'm not really ready to start selling, unless it is to upgrade an item, or buy something that I've always wanted.
After all, I'm only 71, and hope to have many more years to enjoy this wonderful hobby of ours!!
Also, I'm still working full time. I'm trying to learn from my mom. She retired when she was 60, and lived to be 96. She often told me that she wished she had kept working, not just for the income, but for many other reasons as well, like continuing to do something she liked. Well, if I go unexpectedly, my family know not to let the unwanted guns go too cheaply....and neither of my kids really need money from me, both are sucessful, so I'm going to at least keep my favorites for the foreseeable future.
Best Regards, Les