yitzy99,
the reason you don’t find CY gallons is because of a law that regulates the price of a gallon of milk, which currently in NJ is somewhere LESS than $4 a gallon. that law doesn’t apply to half gallons so the CY companies can have you pay $2.79 per half gallon ($5.58 gallon) and make money that way.
There is something in the law that allows you not to fall under the regulation IF you sell less than “X” amount of gallon containers which is why the “special” brands are priced high. If CY went to mostly gallons, they would fall into the regulations.