As usual, alerting you to the random ebook sales I stumble on!
Cuckoo's Calling [Kindle Edition] by Robert Galbraith/J. K. Rowling
Current Amazon US price: $3.29
The Man with the Electrified Brain: Adventures in Madness (Kindle Single) by Simon Winchester
Kindle singles are short - this one's only 44pgs. But it's also free!
With all Amazon sales, when the prices are very low they usually expire quickly. Hopefully by the time you see this the prices will still be accurate!