Americans will pay more for goods produced in Mexico in 2011.
This is a situation of devaluation of the dollar in relation to the Mexican peso. If in 2009 the dollar was worth 16 pesos, but in 2011 it is 14, it means that the purchasing power of the dollar in relation to the Mexican peso has decreased, although it is still high.
In that case, for an American to buy products produced in Mexico in 2011, he or she will spend a little more dollars than he or she would spend in 2009. This is common, since the currencies fluctuate according to the financial market . Thus, the dollar can be valued or devalued, as happened in this example.
If, for example, in 2015 the dollar will buy 20 pesos, it will mean that the dollar appreciated in relation to the peso, increasing the purchasing power of Americans for Mexican products.