I didn't want to tie up $900 of my money to reserve our cabin for me and my husband, so what I did is I reserved the cruise in my name only that way it was only $450- one person. When I could, I added my husband which dropped the price of the trip substantially for my portion as they charge you more to go alone than with 2 in the cabin. The reservation agent told me that they might cancel the reservation if I didn't pay the $450 for my husband within 24 hours, but they didn't. I got us both added for the original $450 and kept it that way for about 6 weeks until I had to pay for it in full. No issues. I'm going to always do that so I don't have to lock up more money than necessary. Remember.. your only concern is reserving the room..
Happy Sailings!