Its the most expensive one stop ticket price apparently for the mileage between the two stations, summat like that anyway.
Just checked a return ticket is £6 for 8 minutes and its only 7.5 miles.
Is the Network Rail area the only system in the world which does NOT have a basic kilometric fare structure? I know many other railways have a variety of discounted tickets but there is usually a base fare related to/proportional to DISTANCE. I think this nonsense all started in BR days in the 1970's with something called the 'Selective Pricing Manual'. In the days when my dad worked for the Southern Railway and then BR Southern Region they used to "cook up a fare" for unusual journeys for which they did not have printed ticket stock by using mileage tables.