I would look at it that you got a bargain on shipping for the more expensive cards.
At first blush I agree with you that that language doesn't make sense. I assume it's just boilerplate and that if an item did get lost Al would cover it and submit an insurance claim, but I can't speak for him of course.
__________________
My avatar is a sketch by my son who is an art school graduate. Some of his sketches and paintings are at
https://www.jamesspaethartwork.com/
He is available to do custom drawings in graphite, charcoal and other media. He also sells some of his works as note cards/greeting cards on Etsy under JamesSpaethArt.