Since I have been BBQ Catering it seems I have a lot more friends. I have cheated myself out of money by being everyone's "Friend" I finally made out a price sheet and quote straight off of the price sheet---friends or not. I am not employed---I do not cater for fun. I cater to make a living, and my friend's realize this. I have enough experience--now I need money.
How big are the sandwiches going to be----on hamburger buns or on French Rolls?
If you have figured it out that you can make money at $7.00 you may have left something out when figuring cost. You have labor costs --food costs--transportation costs--fuel for BBQ pit costs etc. Do you need to pay helpers--or are they "Friends" that are donating their services. I think 7 dollars per plate seems low, but if your help is free maybe not.
The other problem that has cropped up with cooking for "friends" is that the "friends" do not keep special pricing to themselves, and the next person that you quote for the same meal will be angry with you.
What are comparable caterers in your area charging? I have been through these things the hard way---discounting to friends will cause trouble later.
I also look at other things--if someone is renting a hall for thousands of dollars and leaving for a honeymoon in France---and trying to get me to cater at a break even price, then something is wrong. Do not cheat yourself, but do not rip off the customer either---be good---be honest, and be fair. Please recheck your figures.