Gross profiteering

I cannot see how there can be any way that these fuel prices are acceptable.
This is one of the service stations on the M6, south of Lancaster.
There is some, in my opinion feeble, excuse for prices being high in remote places, but in the fairly central mainland on a motorway! Talk about a captive market. I'm so glad I didn't have to buy any fuel.
I know prices of all sorts of things are inflated at service stations as at airports as apparently the retailers pay a premium, or used to, but this is ridiculous.
This is almost 20% higher both than I paid on Sunday in Liverpool, and than I currently pay at home in Edinburgh, where the market is competitive.
HMMMPH!