Most of the time, pretty much worthless. No cheaper than what you get directly at your airline website, or at one of the online travel agencies.
Once in a while, holy cow! My brother-in-law found a $352 USD all-in from New York City to Buenos Aires (EZE, their International Airport). I love living in Uruguay but it’s one of the most expensive ex-US airfares for the actual flight distance. Likewise, Buenos Aires, Argentina, where many Uruguay visitors arrive and then take the Buquebus ferry across the Rio de la Plata. Rarely can you find a US (any gateway) to Uruguay or Argentina for under a thousand bucks. I once grabbed a Miami-origin TAM Brasil roundtrip to Montevideo for $870, and a TACA (now Avianca) out of San Francisco for a rockin’ $794.
But my relatives found one to BsAs for half that price! LAN, one of my favorite airlines, via a 1-day sale from Cheap-O Air. Sorry, all gone now! Even with the $160 USD Reciprocity Fee Argentina charges all US-passport visitors (once every 10 years, payable only online in advance of arrival, same price as the US charges just to apply for a single-visit visa), this is still a steal of a deal.
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