I've been going to DLR 2-3 times a year for years and I've been to WDW 4 times including once this past January. The big difference between WDW and DLR is the variety. WDW has it all over DLR for variety. Now, DH and I haven't been blessed with children yet, but I usually order kids meals at both CS and TS so here are some tips.
1) For breakfast: if you want to save some money and aren't wild about character meals, check out the Carnation Cafe on Main Street. The food is awesome and it offers some great people watching. The Minnie Meal is my favorite. It's around $6 and it is plenty of food. DH loves his big mickey waffle so he orders an adult meal. With drinks and tip we are out of there for less than $20.
2) Lunch: For lunch I have 3 tips. Try sharing a big bowl of soup at the Boudin Restaurant in DCA. Also, the kids meals at the mexican restaurants in both parks(Mission Tortillas is DCA or Cafe Del Zocolo in DL) are great for something other than chicken tenders and corn dogs. Cafe Del Zocolo is also great for adults because the plates are HUGE and easy to share.
3) Turkey legs! They eat like a meal and are fun besides.
4) Avoid the Trattoria at DCA. The food is meh and the service is the worst I've ever experienced at Disney. Definately not magical.
Anyways, over all, if you plan about $80-100 a day, you'll be in good shape.
Have a great time!