Much thought has been given in advance to the publication of paid books.

This is because there is a precept that ordained persons should not buy or sell. Therefore, all operations related to sales are entrusted to the Sasanasamadhi organization in Japan.

Second, the difference between a free book and a paid book.

When books are made free, they attract a large number of readers and curious people, whether they are interested in meditation or not. However, none of them will have a serious and sincere attitude toward meditation. This is because it is free.
For example, if you are an employee of some company, you know why you work so hard to do a job you don’t want to do, why you go to work even if you are sick, even if your body is in pain?

That is what I mean.

Without money, people today cannot eat, live, or have a place to live. And, moreover, they cannot get information through the Internet. As a means of survival, they desperately seek to earn an income. To earn that income, they need social experience, skills, and mental training. This social experience is not free. And learning a skill comes at a high cost. Similarly, mental training, for example, going to a yoga studio, would not cost under $100/month.

From this perspective, books and information are not free.
I would also like to add that an indifferent reader may be misled but will not understand the content of the text.

The author aims to write this book in the hope that it will be an encouragement to those who are sincerely living their lives, i.e., professional athletes, surgeons, technical workers in various industries, pilots, CAs, airport ground staff, and others who support many human beings in the modern society, not bhikkus or brahmin.

It is indeed regrettable that profits are made from the publication of paid books based on this premise.
We would not make this profit a cost of our own lives and luxuries. Hence, this profit would be spent with a view to the survival of Buddhism. For example, retreats or the establishment of meditation studios in some countries and regions.