Looks interesting, but how does one know you're getting what you think you're getting?
I read somewhere those Japanese vending machines sold 'worn panties' with synthesized fragrance sprayed on them. So who knows.
Apparently in the US, panty trading used to be done in person - via C's List ads. Blokes would meet the 'sellers' - who were typically university students - in their cars, the ladies would be wearing a dress, and slip their knickers off right there and then. That way, authenticity was never in doubt.