I knew packaging was a very large swath of the materials costs, but 50%+ was a bit of a shock to me.
Purchased in bulk, blank 12 fl oz cans run about $0.12 apiece. With all the other materials, it's hard to get under $5 per case. Bottles are a little more. And that's before shipping and breakage - nothing else used in the process has to be shipped, intact, twice.
31% is a pretty stiff retailer margin. 28% is standard in the places I've worked. Not that that's a huge sample size.
Excise taxes also vary widely. Here in CO it doesn't even round to 1%, but there are states that are at 10x our rate.