There are many ways to do pricing and I won't pretend that my method was scientific. Lowering the price of the book may (or may not) have increased revenue. I priced the book this way because I felt it was fair value for the content.
I can't thank you enough for those links to the "A Smart Bear" blog. Both articles were exceptional (and should be read in the sequence above to get the full impact).
These two articles on pricing nicely highlight some reasoning behind low vs. high: http://blog.asmartbear.com/perfect-pricing.html and http://blog.asmartbear.com/higher-pricing.html.