Hello. I regularly travel from Oxford or Didcot down to London on Monday mornings, and back on Friday afternoons. Despite some careful study, I have found the advance ticket situation to be completely baffling, and I was hoping some wise experts could help. I tried calling GWR▸ but no joy there. Sorry if this is in the wrong place.
Welcome to the Coffee Shop.
Very much the right place to ask, but please don't expect an easy or totally logical answer - this is rail
Advance fares are designed to fill seats at times that they wouldn't otherwise fill, so there will be very few of them or just a token offering at busy times, and (as others have commented) they are more likely to be available where there is competition. Prices rarely go down ... it *has* been known, but it's rare.