If you can pull off a 600 head dinner @ $12 per and still clear 28% GP that is pretty solid. Plus, you can add this to your portfolio. Not to mention the number of gigs you potentially will book from the 600 attending the event. As they say in marketing... Of those 600 each of them will tell at least 3 of their friends over the water cooler how good the food was and who did the catering.
My wife and I discuss this all the time. We shoot for 40% GP on our gigs. I would look the 12% as advertising!!! Just my .02.
Big Daddy's BBQ
Concessions and Catering
Louisiana Grill - Whole Hog
30x72 Reverse Flow Offset
16ft Wells Cargo Mobile Kitchen
12ft Full service Mobile Kitchen