Sounds like I'm needed here!
For starters, a dining plan is really only a savings if you plan to eat as it is designed. If you typically will split/share meals, not eat dessert, order inexpensive items only, eat breakfast only, etc, then there's a much smaller chance you will come away with any savings.
Take a gander at the following:
- If you plan to dine at 2 or 3 TS locations per night, then the DxDDP is a good bet. The break even point for deluxe is right around 2/3 of credits spent at TS locations. On DxDDP you receive 3 meal credits and 2 snack per person per night, plus a refillable mug for each of you.
- If you plan to dine at an average of 1 TS location per night, then the DDP may be a good choice. Further homework would be needed to determine if it actually will be a savings or not (a lot will depend on your use of the credits and where/when you go). The DDP you receive 1 TS, 1 QS, and 1 Snack credit per person per night.
- If you plan to eat a mostly (or all) QS, then the QSDP may be right for your. On the QSDP you will receive 2 QS and 2 Snack credits per person per night, along with a refillable mug.
- If you plan to eat at non-DDP participating restaurants, will not typically use all of your entitlements, are prone (or happy with) sharing meals, prefer appetizers but not desserts, or just, in general, won't eat as the 3 options above suggest, then OOP will likely be the best bet.
From what you've listed, if you don't plan any other TS meals, either QS or out of pocket will be the best bet. 2 buffets + 1 other TS and 6 QS meals over 6 nights (the 3 meals you've planned, and the 6 allotted QS meals available on the DDP) will not likely cost you an average of $96 per night (especially since the little one gets to eat free at the buffets and kids meals at non-buffet TS places are relatively cheap). Your $30 per QS meal is a pretty good estimate, most average around $12 per adult and $5-7 per child. Add some sharing in there (with some of the combo meals it's a definite possibility) and you got quite a bit of savings.
And yes, in-room pizza is a horrible use of DDP credits (from a value per credit perspective, not necessarily from a "I want to do it" perspective

). In fact, most 2 TS locations/experiences aren't as good value credit-wise on the DDP. This is purely due to the way that the DDP is set up, and it inflates the estimated cost of each TS credit. This isn't a problem on the DxDDP as much, since the estimated cost of each meal credit is quite a bit lower, plus you get 3 times the number of credits to use at TS locations. It's usually (though, not always) recommended to pay OOP when dining at 2TS locations on the DDP. (More detailed analysis of a full DDP plan would find out the best use of credits vs oop, and sometimes it does make sense to pay for a 2TS on credits).
Ok, all of that above was my typical super-verbose way of saying that it looks like you'd be better served, with that plan, to either pick up the QSDP or simply pay out of pocket

.
EDIT:
Doh, and in that super wordy post, you posted about adding a couple more meals and picking up the DDP

, that would work too.