I haven't read through all of the responses (yet) but I wanted to let OP know that when we went in 2010, we brought pop tarts for breakfast in the room/ on the way to parks, and granola bars & fruit snack for snacks. I didn't touch ANY granola bars or fruit snacks, other than on the plane. Once we were on WDW property, everything was on the
DDP. (we had the same one). Maybe we aren't big eaters, but DH, DD, and I all split 2 CS meals, and ate more often. At night, sometimes we'd get one more CS meal to split as a "midnight snack." We also had like 8 snacks left over at the end of the trip!
We brought $300 in cash for the trip, and came back with over $150. This covered tips (most of our TS meals had tips included), and souvenirs (DH and I each got a mug, DD got some earrings, a bracelet, and a toy, and we got a throw blanket and picture frame for our living room).
In short, we budgeted our meals, only ate when we were hungry, and shared when we could. We did this on our latest trip in Feb of this year as well, and had great success with it. We only brought 2 boxes of pop tarts this time (which is a HUGE treat for us - I never normally buy poptarts) and had a couple of CS meals at our hotel's QS place - waffles! - for breakfast. DH and I usually split one, and DD had one to herself, and we would finish up whatever she couldn't. We also had a day where we went to Main Street Bakery for breakfast - One cinnamon roll counted as 1 snack, and the thing was HUGE! It fed all 3 of us, and we didn't eat again until 1pm!
I also brought a water bottle (Bobble - filtered out the gross FL taste to the water), and each time we got a snack, we asked for a glass of ice water (free). Otherwise, the only other drinks we got were the sodas at meals, and we usually had a beer back at the hotel each night.
Hope that helped
oh, and my CS place in our hotel - they had butter, jam, and Cream Cheese out as condiments... I took note, so that next time we go, I'll probably bring a pkg of bagels and not have to worry about bringing cream cheese.
ETA: I had a bunch of snacks left over at the end of our trip both times... in 2010, I swiped them out at our hotel gift shop for fruit snacks... DD gave a pkg to each kid in her class! in 2012, I had 13 left (10 day trip!) I swiped them out at a snack cart in HS - I got craisins (I use them in salads and baking) and craisins trail mix. I'm STILL eating those things, but they traveled really well.