I will move this board to Help & Questions for you, as this item is priced on the shop search! :) However, I believe this book was a fairly new release, and it seems that there are a few more out there now, so the price has dropped from 50mill. Hope that helps!

They are rather new for people getting hold of them. They had been released at least 2 weeks ago and yet today seems to be the first time people have been getting them from the quests.

Oooh, I see, thanks for the info~! (: