The Print category found on the official website is divided into 3 parts: Book, Calendar, Imposition. Each version of the software is targeted (as the name says), for a different category. Therefore, I suggest visiting the official website to see what are the features of each application. This way you can decide which one to buy.
Also, for the prices, simply click the green Buy Now button found on that page which will take you to the payment section where price is shown.