Retail Sales The U.S.A. / Mexican border is ripe for retail sales of goods from both sides of the border; if you ever get the chance to visit Nogales or Douglas Arizona you will understand as these citizens of both countries are walking back and forth with merchandise purchased from the opposite nation.  (Walmart and Target cannot be wrong). Each of the stops along the BorderTransportationSystem can contain shops and duty free areas, and each can be a source of income for people on both sides of the border.  A small retail sales fee would be collected on each sale for the purpose of maintaining the Rest Area / shopping area facilities. Index of ...