That's the key right there. And this is what so many people miss, especially early on. Everyone wants to cover food costs, and other direct and indirect costs, but paying for your time is often an oversight.
Think about it. Say you made 150 bucks, net of all direct costs, at the end of the day. What's that really worth if all the advance prep time, shopping time, travel time, cooking time, cleaning time, packing up time, took 15 hours in total? Is busting your ass for 10 bucks an hour worth it? If you made even less, or spent even more time on the gig, is doing all of that for practically minimum wage worth it?
The answer is obviously different for everyone, but you need to factor in the idea of paying yourself as well rather than just relying on any cash in the till at the end of the event is good enough.
Even small gigs. Is it worth it to bust your butt for an entire Saturday just to make 50 bucks instead of spending the afternoon fishing, golfing, or taking your kids to the zoo?
Part of your pricing structure should include what you want to pay yourself for your time. Your time isn't worthless, and even though it's a ton of fun to cook BBQ and feed people who end up with smiles on their faces after eating your food, it isn't a charity event. You need to make sure you're making enough money to pay for your sacrifice of time so that you can continue to enjoy it and not just get stuck in a rut of doing it for the sake of doing it.
Just my very honest two cents.