Better yet, all three Dark Tower omnibuses are eligible for Amazon's buy two, get one free books sale.
If you're looking for other King books, we have a full list of B2G1 free Stephen King books at the bottom of this story.
B2G1 Free The Dark Tower Graphic Novel OmnibusesB2G1 Free Stephen King's The Dark Tower (Original Novels)The Dark Tower: The "Complete" Graphic Novel SagaStephen King's The Dark Tower: The Complete Graphic Novel Series.
The Dark Tower 8-Book Box SetMore Stephen King B2G1 Free Box Sets, Hardcover Novels, and Graphic NovelsIf you want all three omnibuses and the novel box set, you'll need two other books to cash in on a second B2G1 free.
Even More B2G1 Free Stephen King Novels and Short Story CollectionsWhile I was searching for the pricier Stephen King box sets and hardcovers, I kept track of every Stephen King book in Amazon's B2G1 free promotion.

The Dark Tower Book Box Set And Graphic Novel Omnibuses Are B2G1 Free At Amazon