something that takes up very little space, I get it. Something to pull out and enjoy, or a bunch of things on display for their looks and variety, or maybe a "I collected the whole set" type of accomplishment.
Or like tools, the more you have the better your choices are when you need to pick the best one to use. Or like expensive cars, they simple appreciate in value and eventually you profit.
But tool boxes? I don't think so. The market is sorta flat. Most are so mass manufactured they aren't uncommon, and the price isn't going to go up. Probably go down as fewer job involve using tools to build and repair