In Norway it's by law not legal to resell tickets at a higher price. That means that all listings on reputable buy/sell sites will immediately be taken down if you try.
It of course still happens, but in a smaller scale. You can't base a business around it, exactly.
What? In my example, Person B buys the change of ownership from person A at face value...its pretty clear how much they each paid.
Absolutely no resale is just shifting the risk to the consumer, and affecting the 99% of people who want to see a good show. If the agency takes away the profit of resale, while still collecting a small fee on change of ownership, and allows customers to have flexibility in changing circumstances...its a win win win.
Or you mean there is a locked down trading platform, and only there can tickets be traded? What prevents additional money from changing hands via an off-platform backchannel?
A law could discourage that, like the one in Norway your sibling comment pointed out.
Banning resale is not about selling per se but banning the changing of ownership. The person who paid is verified to be the one attending.