Thanks to the wonderful suggestions of ricktoronto, I'm flying YYZ-DFW-SCL and back for $1400++ later this month. Upgradable for only 10k miles each way, and it earns 1.5 EQPs with no minimum stay.

Last year, the fare was $1200-1400 and I did 3 of these trips, making EXP by the end of the summer!

These Canada->Chile B fares are truly incredible! (basis code: BLE6MCL)

(By comparison, just try searching USA->Chile fares, then add in the $600 copay and the value of the 50,000 miles for the upgrade! I guarantee it will be higher than $1400.)