What are my options?
Sadly there aren’t any. The fare between Gatwick Airport and East Croydon is historically very low compared to the fare between Gatwick and London. This initially allowed much cheaper commutes, but was rapidly ‘sorted’ at the behest of the Department for Transport. For more background to this, see the following post on this site shortly after the PAYG area was extended to Gatwick: Oyster and Gatwick – The Truth