Highway Robbery!

I'm a very big coffee drinker and usually at home on my way to work I stop by at my local Costas for a small black Americano. I can cope with parting with £1.95. But on the M1 motorway it's nearly a whole pound dearer!!?? Why??

Been to Birmingham to drop off Lucie at my parents and now heading back home. Long day and now the house is gonna be so quiet without the kids for a few days.