The amount of money that a person can sell an ebook for can vary. You should first go to a website that specializes in ebook sales and look up one that resemble the one that you have. Discount ebooks can be found online.
You then look at the length and genre of the book or ebook, and see which ones are the best sellers of this particular type. You should have a good appropriate price for the ebook so that people will think that you have a quality product to sell, and not garbage material with no value.