Amazon does offer a monthly package, or you can just sell on an individual book basis and pay higher commissions. What is best for any one seller will depend on their volume.
Based on my selling experience there, the 'suggested price' that Amazon gives you during the listing process is a joke. If you plan on listing a book there, list it at a price that will make sure it shows up in one of the first few pages of listings, preferably the first.
~Lisa