I don't do bbq catering but I've got a business myself and I COMPLETELY UNDERSTAND where you're coming from. I do my best to help the community, buy local (though it cost more) and support as many things in the community as possible.
But here's what I've learned. A lot of those same people wanting me to support them will not return the favor, including "friends" and "neigbhors". They will choose to bypass supporting me and my local business to save a dollar or two for themselves. Totally going against what they asked me to do to support them. That is the sad reality of it.
So, here's what we've done to combat that. We don't support them anymore. We support those who return the favor. I had one guy who we supported two years ago come back this past year and ask for our support in a situation that involved us spending money with them. I told him we were not going to be able to participate in his fundraiser this year. He was a bit taken back and I could tell he was pi$$ed off but oh well. He never got the nerve to ask why. It was probably a good thing because he would have really gotten pi$$ed off if I would have explained to him why.
But as I told my business partner, I couldn't care less if he got ticked. We weren't losing anything. The guy NEVER buys from us because he wants to save two or three dollars and buy from national chains. That's fine. I cannot tell someone the best way to spend their money. Nor can they mine. So I choose not to support people who come with their hand held out wanting us to support them but they won't return the favor.