There are various platforms that offer tickets (e.g. for concerts) with no clear - and mostly - far too high fees. The fee itself is often only recognizable in the last step, before all data was already entered.
A reference eg. is the website Viagogo www.viagogo.at/
Tickets are resold there which are probably sourced from official outlets and are partly offered at an additional cost of x €. Most of the time it's not clear where the tickets come from in the first place.
Transparent pricing, especially when buying online, benefits everyone.
It is important that consumers are advised, clearly, what fees they have to pay and who is the seller of the goods.
Especially when buying via mobile devices, the information content is often lower and a transparent presentation of all costs, including fees, is necessary.