We buy the more expensive salad greens and spinach and mix them. For 50 people we do 25oz salad greens (I think they come in 11oz containers so 3 of them), 2 bell peppers sliced, 1 large red onion, 2 cucumbers and 2-3 cups of cherry tomatoes in a large bowl for 50 people and that number has worked well for us. We place the salad along with the other sides so people take it as a side and not a pre entree salad. So you can take those numbers and adjust to what you do.
