What are worth? Charge what you are worth or stay out of the business. I can't stress this enough, if you need the money that is one thing, if not charge appropriately. You aren't competing with restaurants because if you were you would be losing money, again those guys are already cooking so to toss on a few more pounds of meat is nothing.
How much are you gonna sell per day? How many days will you be providing this service? How many hours per day? Will this tri-tip be served fresh off the grill? What if they want more than just tri-tip?
We can't tell you what to charge. Figure out what your time is worth and go from there. Don't do the job because you want to come here and say you are in the business. I can tell you that it costs a few bucks to get into the business and you need to be agressive and smart to stay in the business. Consider the cost of wear and tear on your equipment, your body and all the other stuff you never think of when you decide to get in the business.
Now tell me what are you worth per hour?...if you have to ask you cant afford me haha:biggrin: