Figuring profit at this point is very difficult, as you do not have the agreement. If you are providing meats, for the current business to sell, that is a pretty straightforward calculation. But, if what you are talking is a pop-up BBQ stand, then you have to first understand the conditions of the deal. Can you use their equipment, license, etc...who is paying for power, water, etc... Lots to the deal.
Whatever you do, cost times 3, that is where you start. Even when you are not paying for the building, as there are other costs, when you don't have the building, to get your pricing done. You can dial in profit once you understand costs, by refining the knowns.
Meat, fuel/wood, transportation/transit, ingredients, consumables, equipment leveraged over time, and you will begin to see what cost is. Start at 3x that cost broken down to a daily rate.
I'm feeling bearish, and I'm packing a Wusthof Grand Brisket slicer from MABA
"perhaps...but then again...maybe not..."