Advertisements, of course, aren't all bad. By exposing people to life-enhancing products, they can raise their standad of living. Yhey also let people know about more than one company, so prices stay low. As a matter of fact, it is actually illegal for different companies to conspire and set their prices the same. Sometimes, however, the opposite happens: the government of a country can actually set a maximum price on a product. A prime example of this is Mexico, where the government sets a limit on the price of tortillas.
Advertisements also have an inherent tendency to set their prices just below a rounded number. For example, gasoline prices at gas station always have 9/10 of a cent on the end. This is just a trick so that people will think that the price of gas there is lower than it really is.
