It was on Kindle, just downloaded it....£9.99!!! Probably paid over the odds for it but I do get a lot of other good deals on Kindle so I don't mind.I got mine on Kobo, I'm sure it's on Kindle as well.
You should consider signing onto the BookBub website; it sends out daily emails containing lists of ebooks that are available for only one or two dollars, or even for free. Each sale only lasts a couple days, but once you have selected from a list of genres that interest you, you'll probably get a dozen or more selections on each day's notification list. Some books are new titles; others are classics (which are usually free!
It's not ideal if you are searching for a specific title, as the odds of that one being on sale on any given day are virtually nil; but as a place to find interesting new reads, it's tough to beat.
Listen to everything; don't completely trust anything.