Crossway regularly has very good prices on their ebooks. I discovered this morning that they have weekly specials that they make known through an email distribution on Tuesdays.
This week the emphasis is on apologetic titles by K. Scott Oliphint, including a title one of my daughters is reading with me (slowly — but it’s good!), Things That Cannot Be Shaken ($1.99).
Once purchased, one can download the books as Kindle (.mobi), iPad (.epub) or PDF formats.