Where are people paying $18 a ticket? I usually pay no more than $10 on telecharge.com by doing a box office pickup.
Either way, to play devil's advocate...booking systems like telecharge or ticketmaster don't make any money off a ticket sale if a product stays a box office price, as there's rarely any sort of inside commissions. So they have to make money by charging a booking fee. CC processing fees themselves are 3% at least. They are also powering and maintaining said booking software and website. And booking companies have staff too, call centre, IT staff, etc.
If we should get mad at someone, get mad at theatre owners for raising the ticket prices themselves!
"Hey little girls, look at all the men in shiny shirts and no wives!" - Jackie Hoffman, Xanadu, 19 Feb 2008