Except you are losing yourself in technicalities, technicalities which court will not care about. Most judicial systems (including UK) are based on both letter AND spirit of the law : https://en.wikipedia.org/wiki/Letter_and_spirit_of_the_law
Most courts will not convict your only for your actions but for the intention that fulfilled your actions. That's also why in most countries, murder and attempted murder will have the same consequences.
So you can hide your fees however you want, the court will interpret your intentions, and you'll have a hard time justifying your $250 processing fee for reselling a concert ticket.
Enforcement of small-scale commerce is hard, black markets exist, people will go advertise on shady sites if they have to.
Imagine you've instituted this ban, and some concert has face-value $100 tickets that now have $400 market value. The reality isn't going to be "there's now lots of $100 tickets available on StubHub", it's going to be "StubHub has no tickets, and some shady black-market website has tickets available for $400 with no consumer protections".
That said, I'm not totally against this world, since all of these inconveniences will add friction and make it less attractive and profitable to buy and scalp lots of tickets. But since I often find out about concerts kind of late, I'm also happy that there's tickets available for me at any price. I'd probably end up going to fewer concerts if we killed the legal resale market.