We're just back from AKL concierge and I would say if money is an issue, you wouldn't need the meal plan with the concierge. Your breakfast is provided, you can get snacks in the lounge, the appetizers are hot and plentiful. Of course we ate many meals in some nice restaurants, but if we'd had had both services, I think we wouldn't have gotten our money's worth from one or the other. We were a large group though, so with only 2, the meal plan woldn't be that much more, and you could probably spend more than what the plan cost. For us, it wouldn't have made sense.
In our lounge, we did have a salad sometimes, as well as grilled shrimp and other meats, cheeses, grains, juices and such. It could certainly have been a meal of some sort.