Traveling in Mexico often sees the Chedraui department store chain. Pretty to like to visit Chedraui, generally will be relatively large, very good to go shopping, some branches will also sell the food that is made now, what you want to buy can almost find, there are many choices, the same commodity prices will generally be more than 7-11 Convenience stores such as OxxO are a little cheaper. The Mexican peso is probably a dollar in addition to a 20, and mental arithmetic is still relatively easy.