Hello and welcome!!
Since this is your first time going you will need to do a lot of research before hand.
There are menus on allears.net. Click on the link below and the menus will be on the left hand of the screen. (or at least where the restaurant is and that will take you there.)
http://allears.net/din/dining.htm
Look over the menus, not only for prices but for dishes and foods they have.
You will need to pick out what restaurants you "might" go to, what meal you might order (pick out a meal for everyone in your party) and add up each day's meals. Then total your meals for the entire vacation. If the $$ is more than what you would pay on the
DDP, then the plan is for you. If you would end up paying more for the DDP, then you would be better off skipping it.
So you will need to pick out exactly what you would eat. If you are not a big dessert person (even on vacation) then the plan may not save you money.
Or if you do not eat like the plan is set up then it also can be more than you would pay.
Basically to really know you have to do the math for your individual family. As there are 3 seperate plans, but not everyone eats like thoes 3.
Good luck and keep researching, it is the best way to educate yourself for this trip!!