bocadillo
Water Gypsy
You should never buy tickets from thetrainline. For normal (non megatrain) tickets use one of the train operators instead, they don't charge a booking fee.
Thetrainline should still have shown you some advance tickets (look for singles, not returns), but for the same trains it would have been £48 plus the booking fee with them.
That used to be my advice but it isn't any longer. thetrainline sometimes still has a supply of the cheaper advance tickets, even after the train operators have run out. For instance, the EMT website would want you to pay £58.60 for tickets on the same train, even though thetrainline still has them for £48. It is sometimes cheaper to pay the thetrainline booking fee than to book on the individual train operators site.