As a number cruncher, I have to disagree with the math presented above, based on your circumstances.
To determine the break-even credit values, you need to solve for:
3D + 2S + M = 103.57
(That is, 3 deluxe meal credits, 2 snack credits, and the per-night value of the mug credit equals the nightly cost of the plan.)
Well, we know what M is - you'd buy that anyway, you say, and you're staying 4 nights, so that's $4.79/night (at $17.99 plus tax, re-run the numbers if the price has changed from the last time I saw it). We can run the numbers assigning different values to S, using $0.00 and $5.00 to establish a range. So with 2 variables "known", we can solve for the 3rd.
At S = 0, D = 32.93
At S = 5, D = 29.59
But those numbers already include sales taxes, menu prices don't, so divide by 1.065, getting:
At S = 0, D = 30.92
At S = 5, D = 27.79
So, even if you value the snacks as $0, you break even at just under $31 per meal credit, or $62 for a signature, based on menu prices.
So, go look at signature menu prices. With a medium-of-the-road appetizer and a top-end entree each, you'll easily be at $70+ per person on average, especially with a non-alcoholic beverage added, and should rapidly approach $80+ at some restaurants. And that can go even higher by getting a savory dessert such as a cheese plate, if desired.
This means that we can see a savings of roughly $10-$20 per meal, let's average that to $15, so over 4 meals, the savings is enough to cover the cost of 2 of the remaining 4 credits (including the breakfast) each, so to break even, you'd need to get approximately $62 value combined from the breakfast and however else you wish to use the 3 spare meal credits (CS, TS, pizza delivery, room service, whatever), plus 8 snacks.
Let's just say a sit-down, non-buffet breakfast and 3 CS meals. That should be $60+ right there, at roughly $15+ each on average.
So, even without optimizing those credits, you break even plus have 8 snacks as a bonus. Any further optimization goes straight to savings.