Claude Debussy - Prelude to the Afternoon of a Faun

I have tried looking this book up, but I am having a hard time finding out much about it. I know its a reproduction of the musical score with his notes and annotions in red and green, but I don't know the significance of it. It is priced over $250 on Abe Books UK. I know that doesn't mean anything, but I'm just curious as to the significance of this music and composer. Is this a highly sought after thing? Thanks!