That is just a fantastic analysis. We have had similar results paying OOP, only we will throw in a couple signature restaurants and adult beverages whenever we want and still pay 2/3s less than we would if we went with the DDP. While our analysis isn't as in depth, we just purchase gift cards for the amount the DDP would have cost us and charge everything to the magic bands / room and we get even more of an all inclusive feel because we aren't limited by the silly restrictions of the DDP. It's always such a nice surprise to have so much money left over on the gift cards that we can use for other things or our next trip rather than trying to jam 100 snack credits into out suitcases.
I love this idea! I have two trips planned this year and had been pondering the idea of using the DDP for one part of our Christmas trip while we're only staying in a studio. I think I'll use this idea for my summer trip and see where I end up! Trust me, I can use the Disney gift cards any time, I'm a DL local and go there quite frequently. Yeah, those Disney $$ won't go to waste.