I went to a concert that requires you to match your ticket, but allowed you to sell tickets on a site they control for the face value. I think the buyer has to pay a transaction fee as well.

I got the tickets by signing up and they took my credit card, and charged me when I was next in line and someone had tickets for sale. It was pretty neat, though I suspect I lucked out because a bunch of people sold their tickets when they announced vaccines would be required (September 2021).