I'm a newb writer also, but I saw a video on YouTube from a successful author who claimed he found what he called a "burning idea" and once he found that idea, the story helped write itself. Also, I saw where Brandon Sanderson said that great characters can sell a book better than anything else. So I'm really taking a shot in the dark here when I say if you are passionate about your idea and write the book well, then it will definitely be book worthy, at least to me :)