Barry Salter wrote in
:


Gatwick Express doesn't charge a "premium" for purchasing your ticket
on board, and there are/were signs to this effect at Victoria, but
that doesn't stop people from queuing up to buy their ticket from the
Ticket Office! (Usually the main one at that)



However, a cheap-day return cannot be purchased by the on-board ticket bod,
I *think*.

So if you're returning same-day, it's better to get it in advance.