I had a long response typed out, but the simple answer is: Would you waste 3 minutes of your time selling a washer for $0.35?  Get too many transactions were the labor to sell the item is more than the revenue, let alone margin, and you have a business that will fail.  It likely cost more to ring up the sale than they generated in revenue.  Then take their 0.10/washer cost out and the store is not making a killing unless you buy hundreds at a time.