We buy groceries on a weekly basis from stores near our home. We often prefer buying from popular superstores than small shops. This happens because we trust the bigger established brands more than the new entrants in the market.
The bias is logically flawed because none of the stores manufactures what it sells. They just purchase it from the distributors, add the price tag and sell it. We cannot be certain that the stock we buy is unadulterated. It is unfortunate that sometimes there is no check for the food being expired.