I've been thinking about buying these, but I'm confused. Exactly how many are there? DVD Planet lists a set 1 and set 3. Amazon lists sets 2 and 3, with the set they list as "set 2" having the same content as "set 1" listed on Planet. Are there 3 Cadfael boxes or just 2. Or should I give up and just buy these as individual discs? One more thing: Are these worth a blind purchase. I love the books but have not seen any of the TV series. Should I rent and watch an episode first before I buy?