It's called you make a $0.10 jar of sauce, sell it for $5 at no frills and $7 at loblaws.

Either way, you're making hella profit, and you know people at loblaws will buy it for $7 because they are rich and don't want to have to go to a second store.

Just like how gas is cheaper in unsafe areas. They know the people around aren't rich, which is usually why it's unsafe, and that the actual rich people would rather pay more to stay in the safe area.