Graceling by Kristin Cashore for $.99 is today's ebook Deal of the Day on Amazon. No, it's not based on a fairy tale, but it's been a well-received YA fantasy novel, so I thought I would share. There are now two companion books to the book which are not discounted, one's not even released yet.
Book description from the publisher:
Katsa has been able to kill a man with her bare hands since she was eight—she’s a Graceling, one of the rare people in her land born with an extreme skill. As niece of the king, she should be able to live a life of privilege, but Graced as she is with killing, she is forced to work as the king’s thug.
When she first meets Prince Po, Graced with combat skills, Katsa has no hint of how her life is about to change. She never expects to become Po’s friend. She never expects to learn a new truth about her own Grace—or about a terrible secret that lies hidden far away . . . a secret that could destroy all seven kingdoms with words alone.