Amazon has Wiersbe's BE series bundle: Paul's Letters on sale for $1.99.
The package includes: Be Right (Romans), Be Wise (1 Corinthians), Be Encouraged (2 Corinthians), Be Free (Galatians), Be Rich (Ephesians), Be Joyful (Philippians), Be Complete (Colossians), Be Ready (1 & 2 Thessalonians), and Be Faithful (1 & 2 Timothy, Titus, Philemon).
You can find it here:
https://www.amazon.com/BE-Bundle-Enc...+series+bundle