I didn't pay OOP for any full meals, but did use 2credits each for 2 meals.
If I didn't have the meal plan, I might have only ate at 2 or 3 sitdown meals, the rest counter service- not because of cost, but because of the time factor.
I figured 8 table service meals over my 9 day stay would just take too much time, but by spending 2 for Poly's Luau Cove do, and 2 for HDDR, that left 4 table service meals, and gave me "2 nights off" so to speak.
That worked really well for me in terms of credit use.
I still had 1 counter service and 1 snack when I checked out (Used them, had POR put all in takeout containers).
The only food I paid out of pocket for was alcohol, occasional frozen lemonade, and appetizers at the table service restaurants (I was so tired of desserts!). Oh, and I bought bagels from the POR gift shop for my breakfasts.- I did eat all my breakfasts in my room.