I'm looking to book a flight from Lima, Peru to Rio De Janero, Brazil (or possibly Sao Paulo), but I only want a one-way flight, as I will be flying to Paris when I leave Brazil. The cheapest I can find on the common U.S.-centric sites (Kayak, Orbitz, etc) seems to be to buy a round-trip ticket on TAM or LAN (which seem to be the same thing) for roughly US$470.
If I look for a one-way ticket, for the exact same flight, I pay nearly double the round-trip price.
Are there any tricks to finding a cheaper one-way flight when flying in South America? Are there regional airlines, or better prices that aren't searched by the U.S.-based aggregate sites? Or any trick I can use to buy only half of a round-trip ticket from one of these airlines? Or is my best bet to buy the round-trip ticket, but just not use the return portion of my ticket?