There's also Robert E. Howard’s Collected Works on Kindle for $4. All 129 of his stories including Conan, Solomon Kane, Breckinridge Elkins, El Borak, and Kull of Atlantis.

https://www.amazon.com/Robert-Howards-Collected-Works-Breckinridge-ebook/dp/B00BA1HN3K/ref=sr_1_16?ie=UTF8&qid=1485970185&sr=8-16&keywords=robert+e+howard