On Thu, 1 Oct 2009 09:43:04 -0700 (PDT), martin wrote:

More generally, what kind of National Rail tickets is it possible to
buy from a tube ticket office?
Only tickets to destinations in the NSE area? Further afield? Can I
use a railcard?

You can buy tickets to any station in the NSE area (but not beyond,
AFAIK). Only singles, day returns, and season tickets are available.

At LU-run NR stations, you can use a Railcard when buying an NR-only
ticket (e.g. Amersham to Aylesbury, Greenford to Ealing Broadway via
South Greenford). Otherwise, you can't use a Railcard, except to buy
all-zones one-day Travelcards.

Also, I doubt you can buy tickets with an origin station other than
the one where you're buying the ticket, though I've never tried. I
also doubt that offers like GroupSave are available.