Being a single mom of a 9 yr old whose been to WDW with her 5 times now, I'm gradually learning the tricks and the trades of saving a bit of money while vacationing at Disney. I know it does sound like an oxymoron to save $$ @ Disney but it can be done. It's not a whole heck of alot of money but, to this single mom, every cent saved means a better souvenier to bring home for her.
I totally go shopping before my trip and gets snackies & b-fast foods on sale. I then actually pack a pilot's suitcase with the goodies......the small one-serving boxes of cereal, Pop-tarts, granola bars, individual one-serving bags of chips, pretzels, Cheez-its, Ritz-bitz. Also fruitsnack, fruit roll-ups, raisans, dried fruit (apricots) are good. We always eat breakfast in the room. Not only does it save money, it saves time. The kids (and you) can get ready and eat at the same time so you're at the parks right when they open. For the milk part of the cereal, we stop at the food court (we usually stay at one of the Value resorts) on our way back to our room the night we come back from the park. We keep the milk in the ice bucket or the sink w/ice and it's ready for the morning. During the day, we try not to buy anything from park so we pack our back-pack with tons of energy snacks. If we do buy something from the parks to snack on, its usually an ice cream or box of popcorn. We don't save any money for dinner because I make it a point to always have a nice sit-down dinner (Sci-Fi Drive-In, The Brown Derby, etc). Since we've been there many times, we bring our Mug that I've kept from a previous trip and get that refilled at the food court for free. You'd be surprised how much you save on that. Also we buy one bottle of water for the day and refill it with drinking water fountain. We use the water-holder strappie thing from one of our previous trips to carry the water bottle around just like the folks who just purchased one. Since it's usually just me and my girl, we always stay at a Value Resort and always keep a look out for "discount codes" that I get via email and see if we can work a trip date good during the dates that honor that discount code. We just can back from WDW last month and we stayed at the All-Star Music resort for $59.00/night using a discount code. Plus I make sure not to go overboard shopping. These little tips have worked for me and I'm sure I'll find out more during my future trips.