After many trips with my kids throughout the years, and my hubby the dealfinder, we have come to find there are no deals at Disney, but there are ways to save money.
First, in my experience, sit down meals with little kids are not fun at WDW, the kids get tired and over excited and the behavior that goes with that is not pleasant. Plus being that the sit down meals are the most expensive, you could save money by minimizing those
Staying at Fort Wilderness is a great suggestion, in the cabins we have had our best times.
It is expensive, but you can get a AAA rate. There are full kitchens and when our kids were little, we ate breakfast in the cabin, packed lunches (with food my kids liked) and most times would go back in the afternoon/early evening to eat dinner (cookout in Feb was a big hit)
As our kiddos have gotten older(23,21,17), they prefer this as well. We swim, ride bikes, fish etc. There are many small kid activities . The Pioneer Hall cafeteria has a hefty breakfast buffet that is reasonable too.
For a treat, we would go to the Contemporary Mickey buffet for breakfast or the one at the Beach CLub is fun too. Buying a soda and french fries to munch on and an occasional Mickey ice cream kept everyone happy.
I agree that 2 days in April expect long lines and maybe only to see the Magic
Also, go there to enjoy that which is Disney, if you stress about the cost, you will not have any fun. You may want to get a stroller for the 4 yr old, the 5 yr old will end up in it as well,you can rent them there.
Mousesaver.com- we have saved big on our rental car, although Disney now has free transport for WDW properties
Intercot.com- lots of info and a forum with many tips