I personally feel that babies should not be taken on a cruise. And that RCI is well within their rights to charge a full fare.
I have a 1 yr old nephew, who loves looking at pictures and other cruise stuff from our past cruises, and definitely plan to take him on a cruise, ONE HE IS OLD ENOUGH to enjoy it. And I have not even considered RCI or Carnival for this "plan ahead" trip...I have only considered Disney. I feel that children, under the age of 7 or so, dont belong on a ship. They dont know what it is all about, and many times they are annoying to other guests.
And as a medical professional, If your child is not over a year old, I would not reccomend taking it on a cruise ship, or any other "tight quartered" area like this. IT IS VERY DANGEROUS!! A baby's immune system is very weak, and things like SARS, RSV, and many other respiratory illness could be FATAL, to your child. Is that a risk you REALLY want to take??
Anyway, enough said.