I noticed where Hubert said he was looking for a book that gets at the heart of the matter. This is what I tried to do with "Captives of a Concept" ...
"There is only one thing that needs to be known about the Watchtower Society and there is only one way to know it."
It has some different ways of looking at things and offers some 'outside the box' suggestions for helping Witnesses come to notice what has happened to them.
Whereas Ray Franz's books take up 1,100 pages.(and I needed every one of them), "Captives of a Concept" only takes 147 pages. I got the title of the book from page 296 "Crisis of Conscience" (1st Edition).
Not all books are for sale everywhere. It mainly depends on the publishing company who published the book. Many publishers make the author partially responsible for the promotion and availability of their book, especially when the book targets a specific type of readers. I am an author myself, and it costs me close to $600 JUST to have my book available at Amazon and various other large booksellers.
As Bryan mentioned, the discount for large booksellers like borders, Amazon, Barnes & Noble, etc.. can be a problem for the author, because the royalties an author receives on each book are based on the price AFTER the discount has been subtracted. That is another reason why some authors prefer not to have their book available with the larger booksellers. Discounts for such places are usually between 40% and 50%, which cuts the author's royalties in half.