Stansted Express Train

The Stansted Express is a "quick" train that goes from London Stansted Airport to Liverpool Street Station. It supposedly takes 45 minutes, but in reality is not as fast, and it is very expensive for what it offers, i.e., a normal train service but for 25 euros! It is cheaper if you buy a return ticket, but not by much, and I think there are discounts if you buy your ticket in advance. There is also a discount for children under 15 years. It is not advisable to take the train without a ticket, as it runs the risk of being caught, because it's a non-stop train, and you can't get off the train if the ticket collector comes through.