On Thursday, 2 October 2014 23:23:37 UTC+1, John Williamson wrote:

And on one or two occasions, chatting with the shopkeeper, I've been
told he does his weekly grocery shop at a supermarket because it's
cheaper than his wholesaler.

Sounds familiar. When my late father gave up running his grocer's shop around 40 years ago this was one of the reasons he gave.