Sell the tickets with regressive price based on time. Sales starts say 2 months before event, initial price is truly exorbitant, say one million dollars. Price decreases linearly down to zero (or true cost price). At any point, people can see current price and the seats left.
Now every potential spectator is playing a game of chicken: the more you wait, the lower the price, but also lower are the chances that you’ll have a ticket. That would capture precisely the maximum amount of dollars that each person is willing to pay for it.
This idea sounds extremely greedy, because it is, so I can’t fathom that no one ever pitched this in a Ticketmaster board meeting.
My idea, however, was a bit less greedy. Once you sold the last ticket, that would be your actual (and fair) price-per-ticket for the concert, and everyone would be refunded the difference. You’ll never know how low it will go, so you shouldn’t overpay and hope it will lower later. I’m pretty sure Ticketmaster will skip this last part if they decide to implement this.
There are multiple issues with my idea, it’s elitist, promotes financial risks on cohorts poorly capable to bear them, etc etc, but it will definitely fix the scalpers problem. Pick your poison.