Sale pricing The question Why do supermarkets offer sales several times a year instead of all-year-round cheaper prices? Explanation 2.When two supermarkets compete, they vary their special offers to take advantage of those customers who do not bother to go to both storesSale pricing The question Why do supermarkets offer sales several times a year instead of all-year-round cheaper prices? Explanation 2  When two supermarkets compete, they vary their special offers to take advantage of those customers who do not bother to go to both stores