This is another Qatar Airways business promo (R) fare bookable until March 7. It's 25,656 miles from Seoul to Doha to São Paolo to Buenos Aires round-trip. You can have a free stopover in either DOH or GRU.

To get the fare down from $3,019 to ~$2,890, you can either use the promo code QRSUBSCRIBER or book 2+ passengers. (The promo code and the multiple-passenger discount seem to cancel each other out if put together.)

Example:
ICN-DOH-GRU-EZE 05/16-05-28 -- $2,890 per pax