Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Infuriating pricing by Amazon

I'm cheating here, 'cause I didn't buy this. I was about to. But Amazon wants nearly 20% MORE for the Kindle edition than they do for the paperback. So, by (a) shelling out big bucks to Amazon for my Kindle, (b) saving Amazon their entire cost of a physical book, and (c) saving Amazon the cost of shipping it to me (I'm a Prime member, so they'd pay the shipping) I am expected to pay them 20% MORE. I am outraged. Send a message to Amazon: do not buy this book on Kindle until they price it appropriately.