There are several factors that go into the cost of ghostwriting. Are you giving me existing material that needs edited or maybe just tweaked, or am I writing from scratch? Will I have to do any research? How long will the book be? (I can help you determine what its length should be, by the way, if you’re not sure.) When do you need it done? In very general terms, you can expect to pay somewhere around $35,000 to $45,000 for a decent-sized book. But I will always give a firm price up front.