We just got back from a 9 day stay at the POP. We took breakfast items and kept in the room. Not only did it save a lot of money, more importantly it saved time!!! My DD's were able to eat in the room while I was getting ready and we were out the door and able to avoid crowded food court area in the am. We took pop tarts, applesauce, single serve canned fruit, muffins, pastries etc. Also, if is worth the effort to take snacks for the park too. Of course you are going to spend some money the popcorn and ice cream are so yummy!! But being in the park in the heat makes for a very long day, so carrying no melting snacks and frozen drink boxes were a life saver! It made waiting for the buses a lot nicer after a long day!
I totally lucked out because my youngest daughter's allergy meds need to be refrigerated and because of the medical need, disney provided my fridge for free. Having the fridge in room was very nice, I would say it would be worth the $$$, I have read on these boards that you can rent them from somewhere that is a little cheaper than renting from disney.