Amazon currently has more than five million classified books. A book gets a ranking by selling at least one copy. Books listed but never sold are not rated. So even if a book has a range of 9,000,000, it has already sold at least one copy sold through Amazon.

So here is my own little graph of how many things can be sold based on the range. Combine this information with the minimum selling price and terms of a book and you can make some guesses about how fast you can convert your selections into cash.