Commodes.
That’s right. Bedpans. The big china ones. I think that as most of America/ Europe/ Australia (at least as far as I understand) is sewered these things will not be produced and will attain some value for their rarity.
It would probably be for my children that I store these things. They won’t make me wealthy. But I’ll buy heaps and put them in the shed out the back.
I don’t mind if you tell your friends if you knew me when I was poor.
I think you mean chamber pots or night jars. Bed pans will have a place as long as sick people can’t get out of bed.
Of course, there are glass, ceramic and metal bed pans that are obsolete. Metal, became a liability when electronic defibrillation became common practice. Roasting one’s butt while saving their life is frowned upon.
That said, I think it might take until your grandchildren are grown for non-plastic bedpans to become rare. They are virtually indestructable.