Weekly ticket cost - Thatcham to Brighton

[whole diary]

[BerkshireBugsy]

Gents, it's possible I may need to commute between the above points. I know from my period of working in Reigate I can get a weekly ticket from Thatcham to Reigate and I suspect Gatwick becuase that is the end point of the GWR^▸ (Great Western Railway) service on that line so  how much would it cost extra to go down to Brighton?

It is possible that I may only need to work on site 3 days but often that makes it worth while getting a weekly ticket

UPDATE:

I've actually used the season ticket calculator on the GWR web site..and it tells me ^142.90 - so I may have answered my own question

[Oxonhutch]

Would it be quicker/more comfortable via London using the respective express services (06:05 start Thatcham)?  Using the previously given formula of Thatcham and Brighton to London Zones 1-6, less a Zone 1-6 Travelcard, I make ^171.20.

[BerkshireBugsy]

Would it be quicker/more comfortable via London using the respective express services (06:05 start Thatcham)?  Using the previously given formula of Thatcham and Brighton to London Zones 1-6, less a Zone 1-6 Travelcard, I make ^171.20.

That is certainly an option worth thinking about...many thanks