Delta and American has round-trip flights from Austin (AUS) to Sao Paulo, Rio de Janeiro, Santiago, Chile, or Buenos Aires (GRU, GIG, SCL, EZE) for $478-$570 with a connection. Extended weekends available. Origin/Destination reversible.
Sao Paulo: Flights in January, March, April, May, and September.
Rio: (Limited dates available) Flights in January, October, and November.
Santiago: Flights March, April, May, June, August, September, October, and November.
Buenos Aires: Flights in April and August.