For lawyers, political scientists and economists, prices are generally conceived as abstract values resulting from global power relationships and interactions between supply and demand. For market professionals, prices are rather the material expression of local calculations, marketing strategies, and merchandising techniques. We would like to reconcile these two views, by looking at the “mundane governance” of prices, at the crossroad of (Main) street level practices and (Interstate) Federal regulation. More precisely, we will present the study of a century of price display technologies in the United States, based on the systematic reading of the trade journal The Progressive Grocer (1922-2016). This study shows that “price fixing” has at least the three meanings: price setting, price hanging and price mending, and that each of these ways to fix prices heavily (re-)shaped consumer cognition and the American economy.