Many successful indie authors do not use ISBNs (for their e-books), and they see no reason why they should. The number Amazon provides works just fine from a practical standpoint.
Having said that, an ISBN gives your book added credibility and has more universal recognition than an ASIN (Amazon Standard Identification Number) when searching for a book by number. So I opt for an ISBN.
However, buying an ISBN costs money. In the United States, buy ISBNs from Bowker. Currently, the standard price for one ISBN is $125, ten costs $295, and one hundred costs $575.
Note that you will need one ISBN for each format your book is in: Hardcover, paperback, e-book, and audio, so that’s four ISBNs. Given the costs, I see why many indie-published authors skip them.
Peter DeHaan is an author, publisher, and editor. He gives back to the writing community through this blog. Get insider info from his monthly newsletter. Sign up today!