I agree that the book is very pricy for what it's showing.
I also think it is a moneymaker for Rising sun. 30-40 US dollar would be an acceptable price (soft cover is OK).
But the book is what it is. In the introduction Takashi Miyai describes that the ook is for beginning and intermediate students. For 1968, this is a wealth of information on Goju-ryu karate.
The dvd is pityfull. Not worth watching.
As for Takahashi Miyagi's karate knowledge, he did spend considarble time training with his father, but probably was not as gifted as Miyagi's top students. But the reason, that he was not considered as a successor by others was because he was in Japan during the 1950ies (work). He even was not allowed to go to his father funaral from his employer. This was considered by the others as an insult.
There has never been real successor to Chojun Miyagi. The family came to a compromis between Miyazato and Yagi and the students voted Higa as president of the Okinawa Goju-Kai. Politics !!!
But you see the book is a clear illustration of how Chojun Miyagi described karate training :
2. Fundamental kata
3. Suplementary exercises
4. Open hand kata
5. Kumite practice
Good book for beginners and intermediate students to show what is karate training about with examples shown in the book. Just need a good teacher to learn it.
The book isn't worth 100 us dollars and shows nothing a serious Goju-ryu practitioner does not know already. Maybe just the confirmation that the training described by Takashi Miyagi is orthodox.