Cuffley-London Terminals is £1876. Gets you to/from Kings Cross or Moorgate (and valid on the Tube between these stations, plus Old Street, only). If you would be happy to walk or cycle to work this would be the easiest way to make a decent saving: it's around 30 minutes' walk from KX which is not far off the time it'd take by Tube, cycling would be quicker of course. The Oyster/contactless fare is £2.40 Tube or £1.50 bus - so even if you ended up using the Tube most days you'd be no worse off (two peak journeys on 220 working days = £1056).
Any annual season ticket will be issued as a Gold Card, which gives you 1/3 off off-peak travel within the South East (with a few extensions), and can be added to your Oyster card to bring the off-peak Z12 single fare to £1.60.
Finally, a note of caution: tickets on this route can be issued on a smartcard. I would stick with a paper ticket - there are still a lot of bugs with smartcards to be ironed out, no real advantage and no price difference.
