Not possible, in sealed good condition. Rest you can risk your 30-35k to save 5k and get an abused 6S 64gb.
@crossfirex
Apple or some carrier certified pre owned - Ok. They are not always repaired, many times they are just customer returned items which are later re-conditioned as new.
By law, a set once used cannot be sold as new, so they are re-conditioned and sold as certified pre owned abroad. Here in Pakistan, they are sold as brand new in abundance, activated and non activated etc.
Non Apple certified - risky, especially in online buying where you cannot check at the spot.