Agree with you in general. It looks like you are staying 5 nights. The calculation is $16.55/day x 2 people. That's $33.10/day x 5 = $165.50. Let's look at table service food you might order because it's "free." If you got the $30 dish, non-alcoholic drink & dessert, you could have a bill of $100 for 2. The
DDP pays the food bill, and covers the tax, but doesn't cover tip. Tip is calculated at 18% at WDW. That one meal tip would cost you $18. 5 nights' meals could be upwards of $100 in tips OOP. These calculations don't even discuss OOP alcohol, tax and tip. Alcohol could bring your OOP expense up another $30. You might want to re-consider QSDP (free) and 1-2 table service meals OOP. That would bring down your extra dining expense considerably.
You still have to buy breakfast OOP. Best thing to do is bring cereal, pop tarts, breakfast bars from home. The resort has milk, bread, fruit, other breakfast stuff, so you could do breakfast relatively cheaply.