Delta, Comfort+ from Santiago, Chile, to NRT, HND, ICN, PEK, and PVG, from $1,287. Good availability on Sep '17, Oct '17 and from Mar '18. Bookable on delta.com.
Sample
https://goo.gl/flights/MBYL
Ex-EZE more expensive, but still reasonable at $1,537. Skimpy availability.
Ex-GRU, EX-GIG from $1,810. Good availability.
EDIT: Not a premium fare. Got Y+ and W+ mixed up. if possible, lock.