DADGUMMIT!-While it is very tempting to carpetbomb your area with your bbq, it may backfire on you. If you lowball everyone to get the word out, you are just hurting yourself down the road. I have maintained my prices for three years, and am now just getting to the point where people realize what a value they are getting from my services. I am usually about 10%-25% more on my prices than my nearest competitor (who also owns a restaraunt), but the difference is in quality and customer service. Once word gets out that you are a better value, just sit back. I rarely cater in the 100's, but the parties for 25-75 people are my main income.
When you get 10-15 people from those parties to notice what they are eating, they are the new customer. In this biz it doesn't happen overnight. It takes time. If you are patient, maintain your quality, and have excellent customer service, you will be cooking for money every weekend.
Good Luck in your endeavors.