Babies are not luggage.
Cruises are awesome. You get on and unpack once, they give you craploads of free food, nightly entertainment, children’s programs, and you can wake up stress-free every morning with a new city to explore. But yes, it’s true, every person in your cabin has to pay the same price, regardless of whether it’s a 400-lb man who eats his body weight in lobster every night or an infant who gurgles, coos, and rapidly expels whatever food it does consume. I know it sucks. But doing this (and charging an insanely high price for a Coke) has kept cruise lines afloat for decades and will continue to do so. There’s no way around this.
Babies cannot be classified as luggage. Stop laughing, I have been asked this more than once by very serious, loving parents. Yep, they’re small, can weigh slightly less than your standard suitcase and have to be carried everywhere, but that doesn’t mean they let you stuff them in overhead compartments on airplanes, either (that would probobly violate the liquids in the carry on rule, as people are what, 80% water?). Trust me. I have actually called cruise lines to ask this. And, judging by the bored-sounding “no” I keep getting, I am clearly not the first person to inquire. I’m sure there’s some safety rule about having to know the correct number of bodies onboard at all times, and this rule doesn’t apply to suitcases.
But really, would you rather pay for your baby to travel with you, or watch as they get a barcoded sticker wrapped around their handle and are thrown on to the luggage truck?