I live in the TfL wasteland of extreme south-east London, in Crayford.
I currently drive to work a couple of miles away most days,
occasionally walking (it's a horrible walk which involves going up a
huge hill but I like to make an effort from time to time!).

My journey to work could easily be done by bus, but knowing how much
cheaper it is to run my tiny car (about 40-50p/day, all told) than to
get the bus (£1.80/day) never makes this idea seem all that appealing.

Recently though I was thinking that it would do me good to go by bus
every day as the walks to and from the bus stops would add up to more
than the occasional walking at the moment, and I could read the paper
on the bus, which would be more enjoyable than driving - plus there are
the obvious environmental benefits of taking my car off the rush-hour
roads.

Anyway, what would really suit my needs would be a Zone 6 only (or
Zones 5-6) bus pass, but it seems this doesn't exist - it's all of
London or nothing for the buses, meaning an outlay of £540, which
could well be more than I'd spend on the buses in a year anyway!

I therefore began wondering about an alternative plan, which would be
to get a Zones 5-6 Travelcard, for £560, i.e. basically the same as a
bus pass, but valid on other transport methods, which around here just
means National Rail. (I seem to recall reading on this group recently
that even a limited travelcard like this would be valid on all buses
anywhere in London, so this really does seem to be a case of paying
just £20 more for access to Zones 5-6 of trains.)

The advantage of this would be that on the numerous occasions each year
when I currently buy an off-peak one-day all zones travelcard, I could
presumably just buy a Zones 1-4 one instead, saving me, at current
prices, 90p a time. (I assume that 5-6 plus 1-4 equals 1-6, doesn't
it?)

I also assume that this would save me something on a National Rail
Return to London, e.g. I guess I would only have to pay for Sidcup
(which is the last station I'd pass through in Zone 5 - or would it be
New Eltham, the first station I would reach in Zone 4?) to London
return rather than Crayford to London. This looks like it would cost
£4.00 rather than £5.10, so that would give even more of a saving per
trip.

So I guess what I'm really asking here is:
- Does all this sound like an idea that would work and would be
worthwhile?
- Could it cause hassle, for instance when buying tickets for zones 1-4
or Sidcup to London while at a Zone 6 NR station?
- Are there any technical issues related to having a Zones 5-6
travelcard on an Oyster when my local station can't handle Oyster very
well (they can't issue them for instance)? I think a nearby newsagent
can do most Oyster things, but I wouldn't want to go there, for
instance, if I was just going for a train ride to London, since the
newsagent is a bit of a walk past the station from my home.
- Does anyone have any other comments about all this, or better ideas?

Thanks in advance for any help or advice you can offer,

Paul