How much does a baby cost?

How much does a baby cost?
No, before someone suggests it, I'm not looking to buy or sell one on the black market, I mean how much do they cost a cruise line once they're onboard in terms of food/entertainment/upkeep etc.

The reason I ask this is that NCL cruises has just announced that they will be scrapping free child places under the age of two. Any children that now fall into that category will just pay the standard discounted rate that any third/fourth guest pays.
Which leads me back to my original question - How much does a baby under the age of two cost a cruise line?

Depending on the babies age they may or may not need food, (they may be still be breast feeding/on the bottle). If they do need food they're obviously going to eat a lot less than an adult. At aged under two they wont be spending much if any time in the kids clubs, (and when they do they have to be accompanied by a parent) and they're likely to be back in their cabin early so wont need any entertainment of an evening.

How then do cruise lines justify charging so much for them? I'd say "for shame NCL" except for the fact that they're not doing anything different to 95% of the other cruise lines. One of the only cruise lines left now giving free places for children is MSC,  (and that's free for anyone seventeen and under), so my best advice for families would be to look at them.

Happy cruising