Once Stripe is connected to your Bubblin Account you'll see the following three options on the Pricing tab:
Note, all transactions will be in US dollars only.
By default a new book is always unpriced and unmarked. If such a book is published all of its pages will be available for anyone to read for free. To price your book simply set a book_price (in cents) via the overlay. The minimum you can sell your book for is 51¢.