How much does pancakes cost for 100 people?
Pancakes are mostly flour, eggs and milk, so the cost is rather negligible. It also depends heavily on the recipes, your choice of ingredients, your location, the number of pancakes per person, the size of the pancakes, and if you include the "dressings" such as sugar, maple syrup, etc.
For example, between an old fashioned and a modern recipe for 100 pancakes, you'll need 5 to 7 pounds of flour, 1 to 1.5 gallons of milk, 1 to 2 dozen eggs.
The total cost would go from $14.5 to $45.5 for 1 pancake per person, from the most basic recipe and the cheapest ingredients to the richest recipe with organic ingredients at today's supermarket prices (June 2012).
Multiply that by 4 if you serve 4 pancakes per person, and add the price of maple syrup, orange juice, coffee, etc.