By the time I got back into National Rail today it wasn't offering me the ^53.80 option anymore..in fact it was at least double that.. And I didn't have that much time to spare.
In hindsight, maybe with them too, I needed to enter railcard type.. Although I certainly didn't do that the other day when it offered me that option..
No wonder people find it confusing.. Also... every time I've gone in to find out my fare options I've been offered different value fares.

Maybe I'll just stick with Maidenhead to London in future.. That's nice and easy AND
always the same price (apart from peak/off peak difference)...