This isn't really new, but a breakthrough for motorway service stations.
For the last couple of years it has been impossible to get a sandwich for less than £3 or a 1 litre bottle of water for less than £2. In fact at some franchises I've seen sarnies for £5 & a 500ml bottle of water for £2.50!
Well if you need to stop on the motorway look out for M&S simply Food outlets,where you can get a cheese sandwich from £1.15, lots of other sarnies for £1.50, & 1 litre bottles of water for 49p!
I know it's not cheaper than tescos etc. but for stopping on the motorway it's a bargain!