To original purchasers only, we gladly offer the right to acquire at a nominal “repurchase” price (currently 50% of the full retail price) the most current edition of a previously purchased Sonlight Instructor’s Guide. Simply place the current edition of the Instructor’s Guide in your shopping cart. The system should recognize that you previously purchased the Instructor’s Guide and will automatically apply the discount. If, for some reason, it doesn't, please add a note in the comments section and our Ordering Department can research your account and manually apply the discount. We offer more information about our Repurchase Discount Policy here: http://www.sonlight.com/repurchase.html