For 1, I'd suggest going back in time a few weeks and booking earlier.
In the absence of a time machine, try splitting your journey into shorter segments and see if you can find cheaper single tickets available.

Try changing at Doncaster, there are far more London-bound trains down that line and thus a greater possibility of finding cheap seats.
( The Mock TurtIe ™ --- Thinks you are a cunt, on, Fri 12 Jun 2009, 18:25, archived)