Ask for a picture of the box you shipped it in
https://www.dropbox.com/s/1wnavvjp1cewjxm/IMG_20160526_165505726.jpg?dl=0
It’s the buyers responsibility to pay for insurance, if desired
So PayPal won’t judge in his favor if he makes a claim? His motives are revealed by asking for $20 instead of a replacement box. Its like asking Solomon to cut the baby in half.