What a wonderful project the Leihbar is! My local MakerSpace has something similar, but it’s pretty unofficial, you just have to announce what you’ve taken in a public chat.

I’ve often had the problem that I’ve needed a tool and borrowing it from Obi or similar cost more than half the price of a new one so I just bought a variant from Parkside for cheaper or similar price. Keep up the good work!

An interesting twist on this, would be to hold the used item while "paying" for it with a collateral. It would remove the need to have an owner to which the item must return to, allowing it to behave more like a linked list, reducing the amoutn of trips by two.

I also think that for taxeable purposes this would work better than buying and selling used items, especially in countries with gross income taxes. In the rest of the cases at least it would reduce the administrative burden to prove that ones net-income or value-add was marginal or negative.