I think a middle ground is observable in where retailers choose to focus- Walmart is targeting 'price first' customers, Costco is targeting 'quality with value'

I think a middle ground is observable in where retailers choose to focus- Walmart is targeting 'price first' customers, Costco is targeting 'quality with value' customers, Whole Foods is (or at least was, pre-acquisition) targeting 'quality first and sometimes only' customers. Customers get to outsource the detailed choices to the retailers and the retailers enforces the desired quality/cost ratios on their suppliers.