I'm not a shoe person, I got a bunch of Nike shoes in a storage unit auction.  all look in pretty good used condition, most had the original boxes and packaging, even some had receipts from original purchase.  I don't know how to authenticate but they look pretty good to me.  Please do check the pictures as they are part of the description.  Some damage to the box as you can see.  Might need a little cleaning, sold as is, you get what you see, any questions please ask.