Firstly, Great topic!

Ive been with the same camp for quite a few years. I found this summer that we have actually haved a lot of money by serving family style, but I found this to be the key, portion control.
We found it best to get table counts and put those up in the kitchen. Here is the important thing. Only allow staff and/or cit/leadership (great oppertunity for teaching responsibility). Make sure they are wearing gloves and serve the food. If you do that any leftovers meets the standards to be reused. Have whoever is serving go for seconds if needed.
With this method, and using us foods and food banks we actually only spent around 12,000 to feed roughly 100-110 campers and staff for 6 weeks. I strongly advise the use of foodbanks for fresh produce!
The thing I really found difficult with buffet is how crazy the mess hall gets with everyone running around. Anyone else had that problem?