Also, when you book your reservations in two like that you may have to change hotel rooms in the middle of your stay. Now, some people don't mind that, but I find it a bother. Disney will TRY to keep you in the same room, but there is no way to know if they can or will until that first departure day arrives.
Here's the thing about paying out of pocket for an additional table service meal. You need to run the numbers with menus in hand to see if it will save you money. The way my family eats on vacation, it's usually less expensive for us to upgrade to the deluxe rather than pay for an additional meal. The upgrade for 2 being roughly $80 a day, and one more nice table service meal dinner for us often being more like $100-$150. However, if your paid for table service meal was say, breakfast at BOMA for 2, that's only an extra $50 so out of pocket saves you more money. Dinner at BOMA would be $80 for 2, so that makes it an even trade. If you pay out of pocket would you be ordering just an entree and a drink, or would you also order appetizers and desserts like the dining plan gives you?
To really see what is going to be most cost efficient you need to weigh 1) where you want to be eating, 2) how much you will spend eating there and 3) how that cost compares to the deluxe dining upgrade.