Hi,
The cost of a picnic can vary. For our last picnic, we were at a resort & hotel center in Olive Branch, MS, and we had to use their hotel caterers for our picnic. They had very nice indoor and outdoor facilities, but their cost for catering the picnic was 20.00 per adult, half for children.

A lesser expensive route is to hire your own caterer for the picnic. The least expensive route would be for family members to cook and serve the food. I am not really sure, but I'll say that picnics normally range from $10 to $15 per person. Therefore, for 100 people, you might be looking at a total cost of $1000 to $1500. Others here on the forum may can give you some more insight.