I seem to remember a couple of years ago that the fare from St Albans City to any London overground terminal was the same (as long as you stuck to overground). It meant you could travel to Charing Cross by changing at London Bridge and the fare would be no more than travelling to St Pancras. I can't seem to find this fare any more, either on the ticket machines or on Trainline. Off Peak return to St Pancras 10.50, off peak return to Charing Cross !5.50. Have they done away with the London Terminals group as a destination?