Just a cautionary note ... if crediting to AA, before booking, I'd check with them to confirm how many miles you'll actually earn, because as of Jan 1, LAN is cutting earning on the lowest economy class international fares. I'm assuming the changes will apply to those crediting to other OW programs as well.
Basically, LANPASS members will now earn just 50% on LAN's cheapest international fares, which had been earning 100% until now. And the cheapest intra-South America flights already earn less -- just 25%.