Sorry not to have been able to post this before now--I just now came across the deal. The deal ends today, May 2 (it started only yesterday).
Warren Wiersbe's
Be Obedient (Genesis 12-25): Learning the Secret of Living by Faith, one of the volumes, of course, in his lauded "Be" series, is currently
free. I know that that is the case at Amazon (mobi) and Christianbook (ePub, DRM Free), so I feel sure that other vendors have the same price.
I checked my library at Amazon, and was surprised to note that I had not yet acquired a copy from Amazon (oddly, I had one from Christianbook (the reverse of how it usually would be)). So, I have taken care of that anomaly, by grabbing one from Amazon.
Here's
the webpage at Amazon for the book, and
the Christianbook webpage
NOTE: between the time that I started this post, and now, the price at Christianbook increased to $8.99! I am at a loss to know why. I thought that it might be because of my messing around with the URL; however, I checked on my cellphone, which has a different I.P. address of course, and it showed a price of $8.99 at Christianbook also.
If you don't want to buy from Amazon, you might consider checking the prices at such vendors as Google Play, Kobo, B&N/Nook, and/or the other usual suspects.