Make yourself a budget.
FOOD-The average meal at Disney is about $7-10 per person, kids about $5-$7. If you bring snacks with you & make sandwiches before you come it will be much cheaper. If you are staying somewhere with a fridge I would recommend buying a case of water & some groceries when you get there. Buy stuff for sandwiches, some fruit, cheese sticks, fruit snacks, whatever your kids like. If you go this way you will probably only need about $200 for food + whatever meals you eat out, probably about $45 per meal out.
GAS- To and from Disney, to and from NY, Grocery store, trip to relatives, etc.
SOUVENIRS- Set a firm budget for this, maybe a certain $ amount per child. It is VERY easy to go over budget on these.
PARKING- Disney charges to park =/
EMERGENCY- Make sure you have a credit card or a decent amount of money set aside in case of emergency (car troubles, injury, etc
I hope you have a great trip!
at 5:38 PM on Feb. 26, 2010