We could just hit $15 for the George Muller Collection--tho not billed as "spiritual formation," but rather as "autobiographies" and "biographies" I believe you will encounter and experience spiritual formation and transformation by immersing yourself in Mr. Muellers spiritual journey.
He started out as a hedonist, perhaps as agnostic, until he encountered a prayer group that prayed as though "somebody was really in the room" (Jesus). His life turned around completely and began the process of finding his true calling, after having some initial dreams dashed. His life of faith, running an orphanage completely on faith with zero appeal letters pushes all of us in our quest to trust God just a little bit more.
Bid today and take advantage of this phenomenal series at an unbeatable price. Bid $18 and you might just wind up with it for $15--we are THAT close!