For easy math I figure a 50% yield. As Eman said the yield is higher 60% but this way there is an automatic 10% more figured in and you don't have to add X pounds based on a 60% yield. Also take into consideration... Are you or someone else, serving or making the sandwiches or is this a drop off/pick up job? If the sandwiches have controlled assembly, 4oz is fine. If it is a Buffet, Aunt Bev will make a 3-4oz sandwich but Uncle Joe will fill his plate, 8-10oz and take 2 -3 rolls. You better plan on bigger per person portion, 6oz, so there is enough. You also adjust portion size by Type of Party and Guest make-up...Guys Bachelor or Superbowl party with drinking...You might go 8oz per person and 2 Rolls (6oz per if other proteins). Ladies Shower...4oz per person is plenty. Mixed men, women and children...4oz if other proteins and sides, 6oz per if Pulled Pork is the primary meat...
As far as what you charge, you have Cost (food, supplies, any rentals) plus your Time. I don't charge for time in the smoker, 15+ hours, but if my hands are Dirty, I get $25 per hour. Your market may bear more or less. So for an average gig, meat, coleslaw, beans...Prep time, cook time and cleanup, I got 5 hours in, so $125 plus the total cost of Food. If you are charging Per Person, you can 1) Call around and see what a similar caterer gets per person, and charge accordingly. OR 2) Take the time to go to the grocery, get food prices and calculate your approximate Food Cost + est. Time / Number of People = Price per Person. Note: You make a little less this way because you can't charge what the Pro Caterer's get and you will pay more for food buying Retail. Pro's buy Wholsale...Isn't this Fun?...JJ
So math...100 guests X 6oz portions = 600oz / 16oz per lb = 37.5lb Pulled Pork / .5 %yield = 75lb Raw Butts needed. Also figure..
1.5 Rolls per Person
Light sided, Coleslaw, 2oz per
Heavy sides, Beans, 3oz per
BBQ Sauce, 1oz per