About the books/newsletters you mention, my charitable view would be that they can at best be useful to a total novice. Once you know the basics, you can get better advice here, and there is no substitute for your own research.

To be honest, your post has a few traits that make it difficult to help you. You don't tell us your starting airport. Or how many days in Chile. Or the flexibility in your dates. And after your first post, you haven't bothered with checking the forum and responding to any questions people have. I too was inclined to try to help, but don't know where to begin.

As others have said, around Christmas is an expensive time to fly. You'll find better fares in Oct-Nov or Jan-April.