Different arrangements apply for residential seasons. The most up to date information is released next month (May) on the ATOC site. I believe "The Manual" lists those restrictions for 'leisure travel'. The agreement that underwrites the PRIV Seasons is different.
I have a strong suspicion that you
are valid with a residential (PRIV rate) season ticket.
However, if you work for London Midland or London Overground, contact John Stewart from ATOC RST by emailing him:
John.stewart@atoc.org or phoning him on 020 7841 8141.
If he confirms my suspicions that it is valid then here are the prices (Min 1 month validity).
EBD-EUS Season (route PLUS HIGH SPEED)
1 month: £80.20
3 month: £240.50
6 month: £481.00
12month: £835.00
The 12 month travelcard EBD-Zones 1-6 PRIV (route High Speed) comes in at £985.00. This should not be printed on GoldCard stock, (but if you really want the 'gold' benefits, it's not hard to find someone who will do it for you).