My husband and I just returned from a cruise to Mexico with my brother. We reserved two cabins, one for my husband and I and then the other for my brother and two friends. The two friends couldn't go at the last minute...but we still had to pay for the second cabin at the highter rate with two occupants. We got a refund for the third person, but my understanding is that a single cruiser will pay the double rate...not the single cruise rate because the cruise lines rent out the cabin for two persons. At least that is the way it was explained to us.
If there is a way to get a deal...we would be very interested!!!
My DH and I will be taking a cruise with my mother. She will be in a cabin by herself. I know that with RCCl she had to pay double. Basically she paid for one person what we are paying for two. Except for goverment fee and port taxes. I think it reduced her bill about $100 or so.
I think there are other lines though that only charge 50% additional if you are traveling alone. Not sure whichs ones though. If you are flexible about the line you are one, contact a travel agent and they should be able to let you know.
These days there are not many deals for the single traveler. I sail single most of the time and end up just biting the bullet and paying the extra price.
There are hints and suggestions in the Single Forum on this board and other places. Basically if you have a set time frame, certain ship you want to be on, you will pay anywhere from 150% - almost double, just the way it is.