yall seem to think sparkling sake is a big bottle, it's usually sold in the same sort of size as a big beer. honestly the bubbles don't really enhance the taste of sake much, it's exactly the same except it makes you burp. it's still the same as a normal bottle with thinner glass, probably about the same as a bottle of wine.
if you live in an alcohol-selling country you can probably find exactly the same sort of bottle at the nearest store that sells wine.