No we do not sell ISBN numbers. What are they? On the back cover of most books is a area that has a bar code that contains the ISBN number for that publication. This number is used for catalogs, when stores order your books and sometimes includes the price of the book. Most bookstore and libraries will not order books without an ISBN number.
If you wish your book to be available at Amazon.com, Barnes and Nobles, or your local bookstores it must be in what's called "distrubition" and must have an ISBN.
There are several ways to purchase the number - from a publisher, some printers, or you can purchase one to what's called a block at
http://www.myidentifiers.com
It is recommended that each publication has its own ISBN. This means you will need an ISBN for a hardcover, paperback, Kindle, eBook or any other method you choose to publish. Some people don't add an ISBN if the ebook is downloaded from their own web site and that is the only place that it can be downloaded.