The Westminster Bookstore has three titles at a 60% discount which might be of some interest.
Preaching Christ from Ecclesiastes: Foundations for Expository Sermons by Sidney Greidanus @ $10.40 (60% off). This a helpful resource, especially as a supplement to other more comprehensive commentaries. I used this book when I went through Ecclesiastes earlier this year.
Ephesians, BECNT series by Frank Thielman @ $18.00 (60% off). I have used parts of this commentary here and there and have found it to be pretty solid.
Speaking God's Words: A Practical Theology of Preaching by Peter Adam @ $7.98 (60% off). I have not used this resource but it looks interesting. I appreciate the work of Dick Lucas and he has written the forward.
Shipping is free If you spend at least $49.