Automatically process sale of a book to Re-Commerce site (e.g. Gazelle.com)

I need a script which automatically submits sales on so called buyback sites. These sites buy books (defined by an ISBN number) for a predefined price. These sites do NOT have APIs - so you have to manage the sale by using PHP and cURL. I will provide the following information (and the script then needs to automatically process the sale): - one or more ISBN numbers - information of the person selling the book (firstname, lastname, address, etc) The scripts needs to do the following steps: 1) process the sale of all the books via the isbn numbers 2) enter the information from the user for the sale 3) if this is a website that requires creating an account, two scenarios need to be implemented: - if no credentials provided: create an account with provided email address and password and then sell the books - if credentials provided: use the provided credentials and then sell the books 4) the payout of these sites often offer two payment forms: (1) via check and (2) payment via paypal. Please implement that the script may choose between these two options IMPORTANT: This is not a normal sale over a marketplace (like eBay), but a so-called buyback sale. The user sells a book to the store and receives the money directly from the store (he does not have to find a buyer). I need 5 different scripts for 5 different sites: - [login to view URL] (important, NOT the marketplace, but the book sale: [login to view URL]) - [login to view URL] - [login to view URL] - [login to view URL] - [login to view URL] You MUST use PHP and cURL for the scripts.