I certainly do not believe in paying more for a ticket than it's listed price. This is a similar con to restaurants who claim that service is not included.
Playwrights, composers, actors, musicians, stage electricians, set designers etc. etc. flyer printers, ice cream sellers, usherettes! ALL HAVE TO BE PAID and there is no earthly reason why ticket sellers should be paid extraordinarily.
The relatively trivial cost of selling the ticket should be included in the ticket price.
When I book B&B with Laterooms and the like, the cost of their marketing and service is borne by the Hotel out of the advertised cost of the room. Laterooms do not charge me anything.
So should it be with tickets for events.