I purchased the book through Amazon for about $60 USD.It was of interest to me because of my training in the Matsumura-ha. He goes through the history of Okinawa and some of the ancient masters. He focuses on the teaching of Soken Matsumura and his students-Kuda, Kise and Kinjo. The part I found most useful was his explanations of the fighting strategies of "village style" vs "school style" karate.Stepping strategies, body change or tai sabaki, etc.
I had the opportunity to train with Mr. Lindsey one one time and can attest to his abilities. Belonged to Sensei Kise's organization for a few years and had the pleasure of training with him in Okinawa. Have belonged to Kuda Sensei's organization for many more years. The book even included a photo and mention of my first instructor, Greg Ohl.
So for me it was a worthwhile purchase. If you have an interest in old style karate or the Matsumura-ha or just an interest in Okinawan Karate the book should be of interest to you.