Avianca is having another great sale from New York to Buenos Aires! Fares start at $1241.
These fares book into A class which earns 100% in most Star Alliance programs and gives you 1/5 of distance as PQPs for United. In the case of the sample below JFK-BOG-EZE-BOG-JFK you would earn 10752 miles and 2054 PQPs.
Here are some links to Trip Reports on Avianca on their Boeing 787 from GRU-BOG and Avianca 330 from BOG-JFK.
Avianca Boeing 787 Business Class
Avianca Airbus 330 Business Class