You may know his most popular book, The Five Love Languages . This book has wonderful insights and is a must read (IMO) for all couples. The Kindle edition if this title is $3.86 right now (and worth every penny!)
No shipping on these since they are digital editions. But I still wanted to remind you to sign up for UPS My Choice. Great way to track when you have an actual package coming your way.
Also remember that Amazon prices change unexpectedly, so check current price before purchasing (it might even be lower!)