Start your business off selling eggs. You won't make very much profit off of egg layers, but they will help get you into the market and gain customers. Eggs are extremely marketable; I have met very few people who would turn down farm fresh eggs, even at higher prices. Also, get plugged in to your local network of pasture-based/eco farmers. Go to farmer's markets and meet some of these people. Talk with them. They know about the ups and downs of the market in your area.
As a side note, if you haven't already you need to check out your state's regulations for selling raw meats. Better to be informed and jump through the necessary hoops (and there are usually a lot of dumb bureaucracy regulations) than to get caught and fined. It wouldn't look good for your customers either. They want to know that you are on the up and up, and trust is something very important when getting a customer base, especially as a farmer.
I own a small pastured poultry farm (eggs only for now!), and am really rooting for you in this! Please let me know how your operation goes, and feel free to ask me any questions--I'm not an expert but I will tell you whatever I know. It's so great to see other people doing the "pastured poultry" thing, really the right way to go IMO.
Oh, and if you haven't already read Joel Salatin's Pastured Poultry Profits, and You Can Farm, you really need to go and read them!