For those that don't mind going around the would I've found a fare with Korean Airlines into and out of Sao Paulo for under $2800pp.

Itinerary:

09JUN - Sydney to Seoul

09JUN - Seoul to Sao Paulo via Los Angeles (landing on the 10th)

03JUL - Sao Paulo to Seoul via Los Angeles (landing on the 5th)

05JUL - Seoul to Sydney


Not the most disirable way to do but for that price it's worth a look!