Exchange rates have nothing to do in this case to justify a price difference over 100% (still the current rate is the lowest in over 1 year - R$1.00 is currently equivalent to US$0.53, not long ago it was equivalent to US$0.63).
Unfortunately, Brazil is a large economy with a third world mindset still. Brazilians are indeed not yet accostumed with their better luck and manufacturers from several countries (among them, Apple) are so happy to explore that. The fact that Apple Brazil refused to answer journalist questions (not trying to explain the "unexplainable") regarding this topic is a clear admission of guilt.
This is the cause among other things of the increasing number of Brazilian travellers abroad spending much more money to buy the very same things they could buy at home: http://www.nytimes.com/2011/12/28/us...razilians.html
From that article:
"Brand-conscious Brazilians love to use their money cash, above all ranking first per capita in spending among the top 10 groups of foreign visitors to the United States, a list that includes the French, British and Germans. In all, 1.2 million Brazilians visited in 2010 and spent $5.9 billion, or $4,940 for each visitor. Only travelers from India and China outspent the Brazilians, but far fewer visit, and they are not among the top 10."