Prime members only. Amazon has the The Chronicles of Narnia (Paperback Box Set) on sale for $19 with free shipping on $35+ or with Prime.

Includes all 7 titles:  The Magician's Nephew; The Lion, the Witch and the Wardrobe; The Horse and His Boy; Prince Caspian; The Voyage of the Dawn Treader; The Silver Chair; and The Last Battle.