Fare difference between standard and first class.

Could someone explain the fare difference between standard and first class for the following monthly season ticket example?

EGH to London terminals standard class £265
EGH to London terminals first class £451.20
An extra £186.20 for first class. Okay so far.

EGH to London zones 1-6 standard class £344.10
EGH to London zones 1-6 first class £588
An extra £243.90 for first class.
I would have expected first class to be £530.30
WHY the extra £57.70? There is no first class on the underground.
Can someone help to explain this disparity? Am I missing something?

Thanks.

  • If you get a First Class travel card, this covers all the trains within the London Area that offer a First Class service within the London Zones.  For example additional SWR services, South Eastern, Thames Link ect.  This is why a day first travel card is allot more money also.