Ok, so this auction is for the out of print Effigy Mound. This was for sale in the TellTale store for a while and it contains a lot of awesome sketches and concept art. I've got my copy all nice and minty freash, so I'll stay out of this one. As always, below is the link and a picture.
Update: It's over. The seller added a "Buy it Now" price of $40. Whoever bought that got a great deal considereding the rarity of the Effigy Mound.
Here's the auction's link.