US duty free shops have crappy wine offerings. What they have is generally mediocre American stuff at inflated prices and their upmarket stuff is pathetic.

In Japan the duty will have more expensive wine but that's because it is really top of the market wine. I guess the Japanese mentality is why would you haul around crappy wine that is sold in Donki, and the idea is that it is a gift. It's not particularly over-priced. You are paying $70 because it is a $65 bottle of Burgundy. In Newark you are paying $17 for a $8.99 bottle of crapola California wine.

I have flown a lot with wine in luggage (since 2006!) and don't use anything special. Just wrap it well and make sure bottles are not touching or non-padded from the outside.

A small roll aboard, max two bottles and a big one max four. I guess with special packaging then you could get six in the latter.