I am a hard core Coke drinker. I will calculate the price of the soda card, however I prefer bottled over gun soda. Royal Caribbean's is too high. $7 a day for gun soda is too high for me.
We usually pick up a couple of bottles liquor onboard or in port if it is a decent price. We don't stock up the liquor closet because it isn't worth lugging it home.
I do enjoy a root beer but have never thought to order one. I bet many of the bar staff may give you a funny look if you ordered one.