Every morning, Martin Lewis reads his emails and the papers while kicking off the first 7,000 of his daily 23,000 steps on his cross-trainer. And every morning, he makes sure to check one thing in particular: the UK natural gas price. He shows me this on his phone screen when we meet, two weeks before the Budget. It’s £2.14 a therm. We watch as the number, atop a jagged Alpine peak, blinks upwards.