How much? Enough to teach United and the whole industry a lesson, but not so much that it puts yet another airline out of business. Airlines need to rethink this approach.
I’m of a mind that tickets ought to be sold on the basis of recallability where a non-recallable ticket carries a premium, but people maybe would be willing to pay lower prices for a ticket that stands a chance of being recalled (with some compensation).
That may work but I think the Checkbox of minimum 2,000 bump would be better. Call it insurance and charge 5 bucks a flight. Airlines would make millions.