Lee, since you haven't gone on one of the "3rd party tours" that you continually bash, you really have no idea whether they are worth it or not. This is only your own personal opinion and not based on any facts.
These guides spend an immense amount of time researching not only the particular KZ, but also the Holocaust itself and all it entails, and they are very passionate about passing this information on to their guests. The time spent on the train going there and coming back is not spent in silence, it is much more than the 4 hours at the KZ. Explanations given that there isn't time to give in the KZ, and questions answered. Try doing that with an audio guide.
Yes, I personally know several guides that lead tours in various Concentration Camps through-out Germany, and what they have studied and learned is far more than just the classes that any of the Memorials offer. It is an ongoing study, interviewing former internees, children of survivors, attending lectures, and reading new material and papers as they get published. Perhaps I am a touch biased, but it angers me to continually read comments that so lightly blow off their deep commitment. It certainly isn't about making a buck, as Lee seems to imply.
Having visited 3 different KZ, 2 of them twice and 1 of them 3 times now, all I can say is that having a guide with you the entire time can be an intense experience and I was glad that I went on these tours. Never, ever, did I feel it was a waste of money.
Rant over.