Ticketing experts required!!! I commute daily by bus from North
Finchley (Z4) to central London. An Annual Bus Pass costs £440. I am
aware from this group of the benefits of paying £448 instead for a one
zone Annual Travelcard (for any zone except Z1) to receive discounted
tube singles and day Travelcards via Oyster Prepay when I occasionally
use the tube. But because of the 'grouping' of zones (eg Z3+Z4) for
pricing purposes, can I really save any money? What other savings
should I consider? FYI I have a YPR and I always use the bus for short
journeys.

Thanks, Dominic