Some recent price drops by HarperCollins (likely same price at other stores or will be soon):
The Strain by Chuck Hogan and Guillermo Del Toro ($1.99)
The Lace Reader by Brunonia Barry ($2.99)
The Haunting Hour by R. L. Stine ($1.99)
Nightmare Hour by R. I. Stine ($1.99)
The Recipe Club: A Tale of Food and Friendship by Andrea Israel and Nancy Garfinkel ($2.99)
The Pilgrimage by Paul Coelho ($1.99)
Veronika Decides to Die by Paul Coelho ($1.99)
Warrior of the Light by Paulo Coelho ($2.99)
The Blessings of the Animals: A Novel (P.S.) by Katrina Brittle ($2.99)
Very Valentine: A Novel by Adriana Trigiani ($2.99)
In a Perfect World by Laura Kasischke ($2.99)
The Weight of Heaven: A Novel (P.S.) by Thrity Umrigar ($2.99)
Husband and Wife: A Novel by Leah Stewart ($2.99)(discounted during a previous sale)
The Summer We Fell Apart: A Novel by Robin Antalek ($2.99)
The Life You've Imagined: A Novel (Zielinski) by Kristina Riggle ($2.99)
Commuters: A Novel (P.S.) by Emily Gray Tedrowe ($2.99)
Light of Day (P.S.) by Jamie M. Saul ($2.99)
The Safety of Secrets by Delaune Michel ($2.99)
Originally HarperCollins in paper, appears to be be self-published ebook:
Stigma by Philip Hawley Jr. ($2.99)