I keep a ton of stuff in my shopping cart on Amazon so I can see easily when their price drops. I would like to do the same with Kindle titles but you can’t. Is there a way either on Amazon itself or somewhere else to get a notification when a title drops in price?
I’ve gotten emails from Amazon when Kindle books on my wishlist go on sale. I don’t recall if it’s all the time or just on occasion, but I’ve gotten a few.
Negative news: I use camelcamelcamel to track Amazon products. Put in a Kindle edition search and they came back saying that Amazon doesn’t let them track Kindle Edition products. 
So outside tracking sites in general are probably a “no”.
There’s Bookbub; a site where you can set up your favorite authors and they’ll send you an email if and when they go on sale.
Track price drops with ereader iq. You need to put the books in individually but they email when the price reaches your threshold, just like camel camel camel does everything else.