I have been studying Market Profile for a while, have read both of Dalton's book's & studied his Field of Vision presentation. All of which I can tell you have advanced my understanding of this form of market analysis. I agree with SpyderTrader & mfbreakout's perspective. I have not yet read cbot manual, Don Jones's work & Steidlmayer's most recent book. All of those resources will advance your understanding of the concept. Personally would not be able to justify the price for Keppler's material, but everyone's willingness to pay & expectation's varies person to person. Regardless, whatever education route you chose, internalization of the concepts will take time, practice, patience & persistence. From that point you may have a statistically quantifiable edge you can work with. Best of luck, Enjoy the process.
-Hopefully this helps you figure out what's best for you