United has flights from Dallas (DFW) to Rio de Janeiro or Sao Paulo (GIG/GRU) for $509 with a connection. Flights sparse and scattered from February to June. 7-day minimum stay required. Flight may operate as a Star Alliance code-share.
Note: Fare allows for a free carry-on bag, but checked bags will cost about +$60 each-way.
Note: Stick to the Example Dates for this one. Other dates may have long stops or multiple connections.
Note: Be aware of the time and season change when traveling to your destination.