B&H currently has a small quantity of open box Nikon D810 bodies selling at $2,900 with full Nikon USA warranty (and free expedited shipping):
This is a $400 savings compare to the price of a new body. No idea how many units they have – they could be sold out at any moment. They seems to have few different listings – check this link (update #1: check also this link).
Update #2: they sold out quickly, but there is another D810 open box for $2,964.95.