If you’ve ever suspected that popping into your local supermarket rather than heading to a bigger superstore is damaging your wallet, then your hunch is correct.

Big brands are cashing in on the convenience and accessibility of their in-town locations and charging around £10 more per shopping trolley.

The BBC investigation looked at Tesco, Sainsbury’s, Marks & Spencer and Waitrose and found huge variations in prices. For example, in a regular Tesco you would pay 9p for a banana versus 25p in express stores. 

The supermarkets say that the price difference is due to the higher cost of running the smaller branches, but the findings offer food for thought for customers who are deciding where to pick up their shopping. 

Not only are the bananas pricey but the investigation found Tesco customers would pay 91p for a bag of mixed peppers in a superstore versus a hiked price of £1.15 in the store closer to their door.

In Marks & Spencer, a banana in a regular store costs 18p versus 40p in their local stores, while red seedless grapes are £2 versus £2.80 in a local branch.

And this all has a big impact on your total bill. At Marks & Spencer the same trolley of shopping cost £103.26 at the Birmingham High Street store and £112.44 at Simply Food in Birmingham New Street Station.

Even some branded products, like Mr Kipling’s French Fancies, varied in price depending on the size of store. In Sainsbury’s the cheaper location charged £1.60 versus £1.95 in the smaller, pricier shop. 

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Shops were visited between September and October this year, and prices were analysed. At Sainsbury’s and Marks and Spencer stores in Birmingham, and Waitrose shops in Shropshire, 45 of 50 items cost more in the convenience location. And at the Tesco Express, 39 of 50 items cost more than in the superstore.

Although the big chains say the varied pricing is a business decision based on overheads at different locations, for those customers who are not able to access larger facilities out of town (for example, if they don’t have a car), the impact is real.