While it might seem a bit restrictive to limit your content provider's pricing options, mandating that all authors sell their books for 1 dollar might be an interesting option for booksellers to consider.
This would create an extremely level playing field, debates about the worth of a particular purchase would be non-existent.
Popular authors such as those in the article, have had success at this price point. This small price model is probably best suited to a direct writer to reader relationship.
It would also bring us one step closer to a copyright free world, where all books are freely traded and compensation comes in the form of donations after the fact of reading.
