But in fairness, what the airlines call tax should be more accurately called "surcharge" as most of it goes nowhere near the Exchequer. Apart from UK departure tax and tax for the country to be visited, the rest is made up of security surcharges, airport passenger service charges, fuel surcharges etc, which the mainline airlines won't include in ticket prices so their headline ticket prices are cheaper which makes for better advertising. EZ of course may not have to charge PSC, but won't necessarily want to advertise that so include stuff like that in the ticket price.

(sorry, subject close to KLM flier's heart as AMS is an astoundingly expensive airport to fly through so we've investigated it at great length, and even have the IATA list of tax codes to make sure we're being charged correctly)