Well, there are no cheap air companies like in Europe, but lucky for you, since you're going to Brazil you should check out Gol Airlines. They are very popular these days and are known to have some of the cheapest flights in the area... (Buenos Aires - Santiago is a LOT cheaper now if you fly with Gol).
So I'd check them out!!
Been to: Argentina, Chile, Syria, Lebanon, Israel, Palestine, Jordan, Egypt. Greece, Turkey, England, France, Italy, Germany, Austria, Belgium, USA, Mexico, Spain, Monaco, Czech Republic, Ireland and Uruguay.
Next trip: Still pondering the possibilities for January 2009... * OH THE MYSTERY!! *
The travel bug is insatiable