〔予約〕Mech R 2の高価買取価格

It appears that you are referencing a specific book or item with the ISBN 9784798640976, which is associated with "Mech R 2." However, I don't have specific details about this item in my training data.
If "Mech R 2" is a title of a book, manga, or some other publication that relates to mechanics, engineering, or a similar theme, I recommend checking with a local bookstore, library, or a database like Amazon or Goodreads for more information about its content, release date, and availability. If you have any particular questions about the book or need information from a related field, feel free to ask!