I will never understand commodity collecting as a form of “investment”. I have a lot of things that have no functional real value, but which at one point or another had some significant market value (baseball cards, mostly). I’ve never bought them with the expectation that the price tomorrow will be as high as or higher than the price yesterday.
I bought them because I wanted to have that thing. And I did. And I still do, because I don’t sell my things, and I especially don’t sell the things in my collections.