Got another one!
This little thread just reminded me that I need a ticket for Judas Priest (hey, it's their last-ever world tour [*]). A quick search for an alternative to Ticketmaster threw up the following:
Ticket face value: £36.00
Booking fee: £4.50
Transaction fee: £5.25
(optional) "cancellation" insurance: £1.50
Total: £45.75 - or £47.25 if you opt for the insurance.
In other words, the surcharge is 27% of the ticket's face value (31% with the insurance)! And I'd love to know what the difference between a "booking" fee and a "transaction" fee is....
And interestingly, despite the fact that processing fees shouldn't be affected by the price of the ticket (same paper, same ink, same database, same stamps, same human resource), a quick look at cheaper tickets shows that the booking and transaction fees were significantly lower:
Ticket face value: £27.50
Booking fee: £2.75
Transaction fee: £2.00
In other words, the "fees" for this ticket are 4.75, or roughly 17.5% of the ticket's face value, rather than the 27% for the JP ticket.
[*] may be subject to change, if a band member needs a new Ferrari. To be fair, JP have been going for over 40 years and haven't got a history of claiming to be retired, so it's more likely to be true than with certain other comeback-kings...