A Greggs sausage roll costs 90p in London but only 50p in Leeds (according to the Sunday Mirror). That seems reasonable to me, considering the difference in rents and wages.
But then I read that an investigation by the Greater Manchester Police into an incident in which a 12-year-old threw a cocktail sausage at a neighbour cost £20,000!
I suppose it's just as well that the "incident" didn't happen in London. Presumably an investigation by the Met would have cost around £36,000, although perhaps less for the non-cocktail variety.
(It doesn't seem possible to order sausage rolls online, but fortunately Mrs F&W is cooking Cumberland sausages tonight...)