Originally Posted by
khkchan
Found the cheapest way to go to central London is to buy a roundtrip ticket on National Rail - 13.6 pound round trip plus a couple more with the travel card option. Oyster will cost 8.1 pound one-way. I believe oyster is capped at 19.3 pound daily. It takes about 45 minutes from Gatwick airport station to Central London with a change of train at Chapman.
Just a small correction. It's clapham junction you are referring to changing at. This only needs to happen if you want to go to Waterloo rather than Victoria. Trains also run to London Bridge, Farringdon, Blackfriars and St Pancras. These are all central London stations.
Also, all of the fares you refer to are the off peak fares. (after 9.30am)