You may want to check out Doug Rauch's new grocery store that sells produce that would normally go to waste in an affordable grocery store: http://dailytable.org/about-us/our-story/
The logistics seem to be the major challenge here. Where will the food come from, how/when does it get to the cook? How do you ensure the cook has enough for all interested people? How does this work for families with 6, 10 or more people? I think for many families, eating a dinner together as a family is important, but how will everyone fit?
Have you considered a potluck model, where everyone brings a dish? Is there a role for "buying in bulk" to reduce meal costs?
+1 for emphasizing affordability! The fewer barriers there are for the average busy family to make these meals at home, the better. I also love the ideas of showing people with different careers to help drive home the concept that you don't have to be a world class chef to make healthy meals. It has to also pass the kid test - love if the food is healthy and affordable, but if kids won't eat it, parents won't make it.