^^^ What he said.
One thing you need to factor in, and this is for any business, not just a food business, is your time. New business owners often get caught up in just the numbers, which are important, but don't tell the whole story. Even if it looks like a profitable venture on paper, what does it mean for your time? Even just a Fri-Sun gig could amount to a 40+ hour workweek. So even if you're profitable, even to the tune of $35k/year or something, would you be willing to bust your ass that hard for $25k/year in take home pay?
There's no right or wrong answer, and some people would love nothing more than to be immersed in BBQ, interact with the public, and see the smiles on their faces while making just enough to pay the bills. But others go into it seeing a potential profitable business only to later realize they are working twice as hard and making half as much as when they had a regular job.
Finally, don't forget to factor in what's required when running a business as essentially a one, or two man show. Obviously, you're cooking BBQ, but you have to wear so many other hats. You have to be a marketing manager, accountant, cook, dishwasher, delivery driver, do customer relations, salesman, etc. For a lot of people, they may be good at one thing, such as making award-winning BBQ, but all the other aspects of running a business are just mind-numbing, yet just as critical as good barbecue. And if you end up having to outsource other aspects of the business, that just means more costs to eat into the profit.
This isn't meant to dissuade or encourage you in any one direction, but just some friendly advice from someone who has started a few businesses and has been self-employed for my entire life. I love it and I live and breathe being my own boss, but it certainly isn't the easiest course through life. But if you look at the opportunity for what it is and go beyond "it will cost X to get started, I think I can make Y, so as long as Y is greater than X it's a good idea" and really think about what it will take to make it all come together, you'll have a better idea of whether or not it's truly a profitable venture.