Actually it is – by leaving the country on a ferry or a bus, for example, since the tax is not a “travel” tax and applies only to flights. That of course makes it about as avoidable as Ryanair’s credit card charges.
Frankly not a single person I know has ever used a MasterCard Prepaid to book a flight.
For the rest of the normal world, Ryanair continues to charge €5 not per single transaction, but per flight.
This is the equivalent of a newsagent charging a handling fee on your credit card twice – once for your newspaper and once for the paper bag to put it into – and after charging you also the total price for both newspaper and bag. So the question remains unanswered – what is the basis for charging €5 per flight when it is a single transaction? Indeed what is the basis for charging it in the first place?