Your customer would have all the interaction with your website, and there would be no link or connection to Bookvault for payment.
The customer would use your payment provider and would pay you for the order. They would pay for the price you set the book and the shipping costs you indicated on your store - which you can either setup yourself, or use our pre-populated shipping rates.
You would then be charged by Bookvault for the production cost of the book and shipping to the customer