To get this deal, head on over HERE and choose your book (any book sold by Amazon) then use code BOOKDEAL25 at checkout! Hooray! You should be able to use this code even if you used the one in November.
You can see all the details of this offer right here. Be sure to check out their 12 Days of Deals in Books too!
Shipping is free with your Prime account or when you spend $35.