John,
Trail-angel to trail-angel, that's all wonderful stuff that you're doing. If I was to tweak it at all for a higher impact/effort ratio or to reduce costs, I'd consider:
Breakfast: French toast, especially if there is a day-old bakery outlet near you. The drier bread soaks up more egg-milk. I find bacon kind of a pain to prepare (but much appreciated by carnivores). Pre-cooked sausage patties, allowed to thaw in advance, could be tossed in a pan and toasted/warmed up very quickly with less effort.
Lunch: Hard to beat hot dogs for calories + protein / dollar. Maybe the PCT cures vegans, but slices of zucchini, eggplant or portobello mushrooms grilled off to the side of the tubesteaks (they should be cooked a little slower), would make you god among the goddess worshippers. Splash a little soy sauce on them for salty flavor and to moisturize them. Then served in the same buns with the same condiments.
For mass-feedings at dinner time (I catered 160 cavers for 3 days in a campground, once), a pot of soup is cheap, and super easy to keep warm and serve as people arrive. #10 cans of anything are cheap. Even cheaper is buy a rotisserie chicken, pick the meat off, boil the carcass in 3 gallons of water to make stock, add meat back in, add onions and carrots plus potato cubes or rice or noodles. Vichyssoise soup is way cheap being based on potatoes, if you mostly use onions instead of leeks. I bet the salad is really popular. Any free veggies available? Often people are struggling to give away their zucchini, etc. Slice, toss in olive oil, sauté in a fry pan and sprinkle with parmesan, salt, pepper, and herbs.
Yes, kabobs are going to be labor-intensive. Spaghetti is the classic easy, cheap meal. Lasagna probably more appreciated. Simple noodles, tossed in butter and sprinkled with parmesan would be popular. A pot of marinara alongside could be another offering to serve on the noodles.
Frozen chicken breasts are pretty cheap in bulk. Thaw, slice, sauté in a pan of hot oil. Serve in a make-your-own pocket bread sandwich bar (lettuce, cheese, condiments). Even cheaper than pita bread are tortillas. Grilled / sautéed chicken breasts and cheese, lettuce, salsa, onions, sour cream in a roll-your-own burrito bar. That way, you only prep the ingredients, the hikers assemble their own dinners.
