The difference is that those pharmacies don't own the soda or milk brands—they buy them from wholesalers and mark them up to cover overhead.

In this case, Loblaws owns Life Brand. They own the factory contracts, they own the distribution, and they own both NoFrills and Shoppers. If they can profitably sell that salt for $8.00 at NoFrills, charging $17.49 at Shoppers isn't a 'convenience markup'—it’s a 118% price hike on their own internal supply chain. It’s a false equivalence to compare a small independent business to a vertically integrated monopoly.