Our first trip (way back when) - what we did to be a buget-wise.
No
DDP - we were
cheap, cheap cheap
If no refrigerator in the room, use a cooler with ice (from the ice machine in zip lock bags which you bring).
We shipped a package to our resort (to us) with cereal, snacks, granola bars, gum, tuna, can opener, knife, pealer, cutting board, small plastic container of mayo.
We took a car service with a food store stop to the resort. We bought bread, case of water bottles, chips, fruit and some veggies.
Buy the refillable mugs at your resort.
Our meals - 2 dinners at our resort of tuna sandwhiches, fruit and chips.
Breakfast in our room every AM.
Some other diners in our room - get something like a burger, pizza, hot dog from the CS at your resort (do take out) - bring it back to your room with your refillable mug drink. Add to your meal some fruit and/or veggies.
We did buffets like CP (lunch), 1900 Park Fair (late breakfast = lunch) and Chef Mickeys(early dinner = late lunch) as our big meals. You feel like you just left a big Thanksgiving feast and will not be hungry for hours.
In the parks the best snack is a popcorn bucket. It comes with a lid and can be munched on all day. Plus you get a WDW bucket sovenier to bring home.
Bring you own water bottles (from the case you bought) with you to the parks.
You can do lunch at a CS in the parks for about $10 for one adult.
APPROXIMATE COST for 7 days & 2 adults:
Breakfast: none
Lunches: 3 buffets about $240 and 4 CS about $80
Dinners: 2 tuna's in room = free, 5 CS with your own fruit/veggies = $60
Grocery stop cost about $50
4 Popcorn buckets (one for each park) about $20 (maybe more)
Total of cheap, cheap, cheap about $450 - But a healthy option with fiber cereal, fruit and veggies instead of calorific desserts and french fries - your body will thank you