When I think about buying in bulk, I think about Costco. Love the prices and I love cruising around each isle eating samples! Buying in bulk can save you quite a bit of money; but how much does shopping at Costco really save? Click the link below to see the price break down or price per unit for grocery items like diapers and cereal. Now, compare the price per unit to what you normally pay. Now you know which items to get a Costco and which items to price match at Walmart. Get ready to save money!