Both on Amazon, for Kindle:

$1.99: Tourist Season, by Carl Hiaasen.  Major Pettigrew's Last Stand, by Helen Simonson.

Currently $1.99: The Unpleasantness at the Bellona Club, by Dorothy L. Sayers.  The Golden Compass (aka Northern Lights), The Subtle Knife, and The Amber Spyglass, by Phillip Pullman.  Jack of Shadows, by Roger Zelazny.  Cheaper by the Dozen, by Frank Gilbreth and Ernestine Gilbreth Carey.

Currently $2.99: Three James Herriot Classics (All Creatures Great and Small, All Things Bright and Beautiful, and All Things Wise and Wonderful), by James Herriot.  Brideshead Revisited, by Evelyn Waugh.

Currently $3.99: And the Band Played On, by Randy Shilts.  Silent Spring, by Rachel Carson.

Currently $1.99: The Judas Goat, by Robert B. Parker.  The Shattered Tree, by Charles Todd.

Currently $2.99: His Majesty's Dragon, by Naomi Novik.

Currently $1.99: The Murder of Roger Ackroyd, by Agatha Christie.  Anansi Boys, by Neil Gaiman.

Currently $1.99: An American Tragedy, by Theodore Dreiser.  2010: Odyssey Two, by Arthur C. Clarke.  A Passage to India, by E.M. Forester.

Currently $2.99: The Cruelest Month, by Louise Penny.  Berlin Diary, by William L. Shirer.  Edward III: The Perfect King, by Ian Mortimer.  The First World War: A Complete History, by Martin Gilbert.