Actually im going to go against the grain here and suggest you may end up getting better value for money (and a more comfortable dining experience) on a meal plan. But either the full board standard or the full board premium. Probably the full board standard.
Food is expensive but not quite as expensive as your sums. Most the fast food joints in the parks (fueta del oro, bella notte hakuna matata the meals range from 14 eur to 16 eur. Earl of sandwich (gorgeous food) and mcdonalds in the Disney Village at the gate are cheaper. Your looking at Cafe Hyperion and lucky nugget salon which sit at a much higher price point of €25ish.
Most of the the fast food in the parks had an overhaul about 18 months ago. What ive tried is definitely better and generally reports are better. Personally i dont find the fast food dining a terribly relaxing experience and tend to prefer at least one meal a day where the food comes to me. (BUT I have one in a wheelchair so buffets are harder and the sit down meals provide a chance for a break).
Meal plans only count nights. So if you are ther 5day/4nights half board you get one meal voucher per person per a night, full board 2. You can use them at any point in your stay. If you like a not fast food meal once a day consider full board as this covers the day you dont get a voucher for.
Value for money works out best like this last time i checked for 5 days...
If you eat all fast food no meal plan (especially if you eat some outside the parks)
If you want to eat at least one meal at buffet level you want the standard meal plan full board. You could eat meal both buffet, and you can use the vouchers at fast food if you want. The standard meal plan and buffets are terrific value for money especially if you have hungry kids and teens. The buffets are also often the the quickest if you want to eat and go.
If you want one or two character dining meals you need a plus meal plan (topping up the character dining. If you want to get out the fast food places full stop you want the full board plus and top up any premium dining you do . You still get value for money if two of you meals you eat of the course of you stay are fast food but not 3)
You dont see the best food dlp has to offer unless you get the premium meal plan especially. You will get the atmosphere of captain Jack's and Remys on the plus. But you wont get the food (other than the steakhouse and the silver spur) unless you pay for premium. If you want to eat at least one meal every day premium but happy to do one ff, you want half board premium. If you really want to see the hest disney has to offered eat full board premium, but this is a massive drain both in terms of cost and time. (And youll never want to eat again)
In your shoes consider the buffets and the standard meal plan. Kids love them
If you want 3+ meals at premium or above (so character dining, buffelo bills,