I bought Sacha's new book, and it's magnificent! Based on how I value my time, I spent more money reading the first chapter or two, and given that I'm going to be starting a Meteor project soon, the quick ramp-up I got from his book is easily worth thousands of dollars. Not to mention the opportunity cost benefit of using Meteor vs something slower to develop with.

$39 is expensive if your time is cheap and your results aren't worth much. It's also expensive if you expect a lousy book, but Discover Meteor is outstanding so far.