I'm not sure what your resources are for purchasing food, but you should be able to increase many recipes to fit your needs. Find recipes that are very budget conscious such as Tater Tot Casserole or Chicken Pot Pie and increase for the number you feed. Many recipe sites have budget meal/recipe sections that you should be able to adapt to feeding so many also.
I found this link http://recipesforacrowd.com/ it's kind of geared towards events, but the recipes offer options for using fresh or canned items, which might make them adaptable for your use.
I don't have any actual recipes to offer though, sorry.
Peace.
Cat