It's really worth buying the boxed set rather than just the cards. As well as an excellent guidebook, it comes with an attractive, excellent quality dark blue covercloth with delightful Celtic designs on it in a silvery colour for when you do spreads with these cards. If you use other oracle decks and/or tarot, you may well want to use this covercloth with other cards, especially with the DruidCraft Tarot, of course, which works so well with this deck.
And if you want to learn more about Druidry, I'd recommend the recently published "The Path of Druidry: Walking the Ancient Green Way", which has a Foreword by Philip Carr-Gomm. A really practical course of study that helps you connect these Druid decks and the teachings of Druidry with life in the twenty-first century urban environment.