I understand that this was an older post, but I've recently did a comprehensive guide of the Patagonia airports with some average ticket prices and I felt the community could benefit from the data.
The international options are still similar to when this post was created (either Santiago or Buenos Aires are still the only options) Some of the regional domestic airports in Patagonia have upgraded and now receive more flights, see the link for the list: Patagonia Airports.

Best regards.