Kringwinkels are a goldmine for stuff like this. We oftentimes get crates at a time, chockful of Weck jars, canning jars, and the ones with the rubber seal and metal wire closing mechanism. We can’t get rid of them fast enough because (almost) no one will buy them, even at 50 cents.
If your local Kringwinkel doesn’t seem to have any, ask the staff, chances are they’re immediately recycling them rather than having them collect dust on the shelves.
Do you have a source for this? (Non-aggressive tone)