DL has D1 awards on MIA-SCL route from 110K miles, but they are seasonally restricted. Also have a lengthy 90 day AP. As far as RDU-SCL, the cheapest D1 awards are 190K each-way, but require a roundtrip award booking. You will never see the 190K D1 awards on RDU-SCL if you are searching as one ways due to the roundtrip booking requirement.
