CAPTCHAs are over (in ticketing)

What about this schema:

The first ticket you buy costs the normal price. The second ticket costs twice the price. The third ticket is four times the price and so on.

Scalpers who buy many tickets at once will go bankrupt before they can buy all the available tickets.

You can even limit max tickets sold to one person at two or three, but the trouble, as I understand it, is that it's hard to identify individuals as being... well individuals.