You can eat great on a $100. a day[many have done it for much less!!]with just a little pre planning!!
AllEarsNet has menu's and prices for most all the eateries in all 4 parks and resorts and Downtown Disney, and the Water parks!!
Check it out
http://www.wdwig.com/menu/menus.htm
Plus there are ton's of tips to save money I'll hit the high points and then if you do a search late in the evening[search works better then] you find tons of info.
1. Eat breakfast in your room. Pop tarts,bagels and cheam cheese, cereal and milk.
2. Eat at counter restaurants that have add your own condiment bars. Instead of putting the lettice on your burger put it to the side and make a salad to go with your burger.
3. WDW meals are big enough to share one idea is to order a double cheese burger then open it so you have bun,burger cheese and now you have 2 open face cheese burgers.
4. Pick 1 or 2 character meals to do during your trip. Chef Mickey is a good choice for a first day or last day meal because it is at the Contempary Resort so you don't need to use a hopper day to go there to eat.
5. Don't pay for fench fries if you won't eat them WDW will take a $1.00 off of a burger and fries.
6. Eat off site,there are many restaurants very close that offer less expensive food
If you need more ideas just ask!