As long as there is a book number, the book must be a formal publication. But different units will have different regulations on whether the articles in this collection are counted or not. Anyway, it is not the scientific research achievement of ordinary colleges and universities.
3. The award certificate depends on what the awarding unit is. If it is an overview of the writing Committee, then this award certificate has no gold at all. Of course, whether it is useful or not depends on the specific appraisal of each unit. Colleges and universities generally do not recognize this kind of reward.
It's normal to pay money, and people also want money for their book numbers. It's obviously for money to issue such a famous book. If your company recognizes the articles in the officially published anthology, you can pay if necessary. But in general, it is better to find an article published in a journal.