In message , congokid
writes

I travelled today from FB to C&L via Baker Street and my Oystercard was
charged GBP6 for the outward journey at about 7.45am, and GBP3 for the
return journey at about 11.15am.

First of all, are these the correct fares?

Yes. C&L is Zone 8. The Oyster single is £6 peak (your outward journey)
and £3 offpeak (your return).

Secondly, this may become a regular commute for me for a while, and I
wonder what my most economic option would be for a season ticket
(weekly or monthly - I don't see it going beyond 5-6 months).

If you are working normal hours and travelling peak time in both
directions, it will be £12 a day on PAYG Oyster. I don't know what a
season would be, but I'm sure somebody will.

This leads me to question 3 - is it OK to take a regular bike on board?

Only out of peak hours (but you could take it all the way from FB if
going via Baker Street).
--
Paul Terry