Do you plan on shopping? Thats where most of my money goes. Having all sorts of things there together to choose from, I almost always find things to bring home? A little piece of jewelry, some knock off hangbags. I bring $50 or so, mostly in ones for tips and haggling in the ports.
I cant think of any Carnival ships that do 5 day cruises that have any pay option restaurants, so I dont think you need to budget for this. There is always free food available, but if you have a sweet tooth, rarely candy unless you bring some from home. Are you the type that a piece of cake will do?
Iced tea and lemonaide and coffee etc are free, but there will be speciality coffee and speciality ice cream some will buy. I do the free.
I would bring a few hundred for emergencies ... like seeing something want to buy. I never use credit cards in the ports.
How about internet access. Its very expensive on the ship, but cheap in the ports for cash.
Conquest 7/21/13, Miracle ALASKA 8/27/13, Miracle HAWAII 9/17/13, Celebrity Summit, 11/30/13, Celebrity Summit, 12/7/13, Celebrity Constellation, 2/7/14, NCL Epic 3/2/14, Allure 5/4/14, Allure 11/2/14