Bring from home (or go shopping once you're there) and buy your own quick breakfast foods and snacks. Granola bars, Pop Tarts, donuts, fruit snacks, etc, AND... buy a case of water, it will save you a small fortune!! Take your own water into the parks (unopened is allowed!) We freeze our water bottles partially before we leave and they slowly melt throughout the day and are plenty cold when we want them later on.
You're also allowed to take in your own snacks. Big money saver!
There's a Wal Mart nearby, they sell licensed Disney merchandise for a fraction of what the parks sell stuff for.... let the kiddos pick out t-shirts and souvenirs there, another money saver!
Staying off site can be a money saver if you're willing. We are renting a condo at Windsor Hills for $89 a night this summer.... 3 bedrooms and sleeps 7. Full kitchen, 2 full bathrooms, lots of room to spread out.
If your local grocery store offers fuel points, or any type of incentive points for gift cards... we stock up on restaurant gift cards and gas cards, accumulate the points, and we'd be spending the money anyways. Double duty spending!
And yes to the stroller. Mine used one for a long time, it really helps. Take a large garbage bag and some clothes pins to cover it in case you're in an attraction, or a restaurant, and it starts raining.