Here is an unconfirmed way to determine if a Nikon camera or a lens has been originally sold as refurbished – if refurbished, there should be two pinprick marks on both sides of the serial number:
Refurbished Nikon gear is sold at Amazon, B&H, Adorama, eBay, Cameta Camera and BuyDig and usually comes with a 90 day US warranty.
Thanks Broxibear!