Ahoy, Katy!
Thank you for another excellent cruise question. You'll be happy to know your accommodations, entertainment, youth activities for ages 3-17 and food are all included in your cruise fare (including most of the 24-hour room service menu)! The only food not included is an adult-only meal at Palo (all four ships) or at Remy (Dream and Fantasy). Also, snacks for the movies and shows outside the theaters are additional. Soda (Coke products) is included when ordered in the main dining rooms and at the 24-hour beverage station. If you order a soda from room service or at one of the bars, there is a charge. Adult beverages and specialty drinks including the coffee at the Cove Cafe are available for a fee. If you plan to venture ashore, Port Adventures are an additional cost along with spa/salon treatments, makeovers and pirate transformations at Bibbidi Bobbidi Boutique (Dream, Fantasy, Magic), Bingo, hair braiding and adult beverage tastings. Transportation to the terminal from the airport or parking fees at the port should also be considered in your cruise budget.
Gratuities are another expense I was unaware of on our first cruise. These can be paid in advance or charged to your onboard account. Souvenirs and photos are not to be forgotten. I plan ahead for these by purchasing one Disney Gift Card each week leading up to my cruise to give to Guest Services. It's a great way to save up, but be sure to hold on to at least one card in case you don't end up spending all the money. If you do have a little one under age three, the nursery does charge a nominal hourly fee.
The only cash we bring onboard is for tips (the porters, room service and excursion guides ashore).
Except for the gratuities (tips) and transportation, most of these expenses are optional, Katy. You can pick and choose how you want to spend your dollars onboard. Hopefully, I've given you a good idea of what to expect.
Nancy