$99.00 per title.
Book metadata is what search engines such as Google use to list your entry (book) so it can be found by using the search feature on Amazon and on Google Search. There are detailed procedures for properly filing your metadata for optimum indexing: title, subtitle, series title, author, contributors, book description, categories and keywords. Every metadata item must match for print books and eBooks and be consistent.
All of these fields are metadata, and they will be indexed and used to make your book more discoverable online.