I read a few articles about the airlines in the last couple of days and I think the cost of tickets may well be the least of our worries - there is the possibility mentioned that unless another agreement is in place there may be NO flights in or out of Uk for a couple of months at least. It will affect American flights etc as well as European ones. It is to do with this One Sky agreement and flying in other countries air space.
Ryanair are talking of taking all their bases out of UK - O'Leary says that aircraft are easy to move but staff or not and it will take time to move the staff who are willing /want to move abroad.