Cooking for 30 with a $24 Budget

Hi Everyone,

I am going to be providing meals once/week for a class I'm in. Well, me and a partner. They have given us a budget of $24 for approx. 30 folks and I don't want to just provide a snack. This is an evening class lasting 4 hours and a lot of folks are coming straight from work. I'd much rather provide a meal. This past week we did taquitos, a hot cheesy bean dip, sour cream, salsa, guacamole, apples, bananas, grapes and oranges and pulled it off for $17 with food leftover.

Here are my ideas so far (we have 13 weeks left):

Spagetti dinner with salad and garlic bread
King Ranch Chicken with salad
Chopped Beef Sanwiches/Potato Salad/Cole Slaw
Chili and Jalapeno Cheese Cornbread
Picadillo/Chips and fruit salad
Carne Guisada with Tortillas, Rice and Beans
Greek Chicken and Pasta Salad

Any other ideas to stretch a buck? Recipes too, please!