If they keep it to the two and a half percent cracker, you shouldn't see a massive increase on say, a £1000 it is when the airlines ect get greedy and start to itemise all their services that the trouble kicks in, they do now, advertise a flight for £89-99 but by the time they put all the add-ons it comes out the other end at nearly £300, I think also you may find in the small print, they can reserve the right to add on any costs passed to them, worth checking