Next week will be using the 06.56 service from Middlesbrough to Carlisle, and back again on the same day. However I will also be using a Tyne and Tees Day Rover (which is valid up until Hexham, after 08.45) for later on in the day. Question is, what is the cheapest ticket that I can get to get me from Middlesbrough to Carlisle and back to Hexham, if there is one cheaper than £15.90 with a YP SOR railcard?