Check out ORD-DFW-SCL in business for $1600 (11k miles, 22k points, if the .5 point bonus counts for the challenge), available Sept-Dec I believe, all AA metal. There is also FRA-DFW-SCL in F for $2,600, all AA metal, 20k miles, and 40k points, if the .5 point bonus counts for the challenge. Check the points that qualify and that you need carefully. Links for both are in the premium deals forum.