Main point
The Gatwick Express takes roughly 30 minutes to reach London Victoria and costs about £21.90. However, many tourists don't realise that standard Southern Railway trains also run to London Victoria, take only 3 to 5 minutes longer, and can be significantly cheaper if you use a Contactless card or Oyster. The Gatwick Express operates dedicated trains with more luggage racks, which is beneficial during rush hour, but outside of peak times, the standard Southern train offers almost identical service for less money.