A number of recent popular mainstream YA novels are currently discounted for US readers (mostly HarperTeen releases, I think).
Shatter Me (Enhanced Audio/Video Edition) by Taheref Mafi is $2.99.
Dark Eden (Enhanced Edition) by Patrick Carman is $1.99.
Forgive My Fins by Tera Lynn Childs is $1.99.
Possess by Gretchen McNeil is $1.99.
Masque of Red Death by Bethany Griffin is $1.99.
Variant by Robison Wells is $1.99.
Die For Me by Amy Plum is $1.99.
Those all seem to be publisher deals, so they may also be available at those prices in other shops.