We stay off property, so we can save a LOT by not eating in the parks as much as possible. We’ll cook dinner in our rental, or hit some cheap fast-food place, etc.
But whether you are staying on or offsite, a big money saver is just eating breakfast and evening snacks in your room. Most have small fridges and microwaves if you want to keep milk and make oatmeal, or cereal. And for in-park alternatives to spending $6 a snack, we’ll sometimes bring in with us Pop-Tarts (which we don’t otherwise generally buy), etc.
I guess it depends on how committed you are to the cause of saving money. I mean, when the kids were younger, and our budget was particularly tight, we’d actually bring lunch into the parks with us, using flatbread to make sandwiches that didn’t matter if they got squished, etc. In those days, eating one meal in the parks each day at a Quick Service place was splurging.
Even up to our last trip, we only did one Table Service meal per trip (at least, on Disney property). Next to the tickets themselves, the price of food is pretty much the most expensive part of our trips, so saving food money anyway we can means we can spend more days at the parks, etc.