Tickets to all events at municipally owned facilities, including the Memorial Coliseum, PGE Park, and the public plaza at the Rose Quarter, and tickets to all events at the Rose Garden Arena other than season tickets, must have printed thereon the retail price thereof. It is unlawful for any person to sell or offer for sale any ticket for an event at any municipally owned facility, or for any event at the Rose Garden Arena, at a price greater than the retail price printed thereon or at a price greater than the original retail price. Notwithstanding the above, this Section may not be construed to prohibit service fees or charges imposed or collected by ticket outlets where service fees or charges are specifically authorized by the management of the facilities.