Of course, timings depend on how quick and how experienced you are. These days I can produce a book in half the time I used to. When it comes to book design, they are usually priced at a page rate. Not so good if you are slow. Great if you are fast. My hourly rate and my page rate usually work out fails similar when the final cost is calculated. When you are inexperienced, this still usually holds true as well, in that your hourly rate is usually less, so if the same page rate takes you longer, due to inexperience, then it probably still corresponds to fairly well to your hourly rate.