Lots of OSR publishers would like to get onto Barnes & Noble ... oddly enough, Rappan Athuk seems to have gotten there without agreeing to be there, on terms that not only weren't authorized ... but wouldn't be approved.
Someone pointed out this link to Rappan Athuk at Barnes & Noble, and it caused a bit of confusion over at Frog God Games, because it is completely and utterly unauthorized. We have no idea why Barnes & Noble is offering the book, since they don't own any and haven't bought any.
The price they are quoting is below the price we would sell the books wholesale, so don't expect that they will honor any orders put through their website. If this turns out to be a third party seller rather than B&N, and we can track who it is, that third party seller will NOT be getting any copies.
In summary, if you hear that you can get a cheaper price at Barnes & Noble, don't expect that B&N will actually come through. This is also technically endangering our agreement with Kickstarter, which is why we are trying to make it absolutely clear to everyone that we have not authorized B&N to sell the books at ALL. Much less at bargain-basement clearance prices.
So unless you're 100% confident in your ability to sue Barnes & Noble to sell you a book when it's at a loss to them, I wouldn't pre-order from them.
EDIT - the only place to get it is from Kickstarter, here.