Here's my 2 cents:
The only way to make a profit raising birds is to:
1. Be extremely efficient with feed (where/how you buy it, or better yet make it or grow it yourself) including keeping the birds from wasting it. For example, pastured chickens will get 15% of their feed from pasture thereby reducing feed costs 15%.
2. Reduce the time/how long you grow out the birds (again its related to feed efficiency). Cornish X is 8 weeks, that's why people raise them.
3. Who does the work ( feeding, caring, butchering). Again, all better if you and your family do all the work, especially butchering and packaging. If you pay someone else for butchering, you may lose your entire profit margin.
4. Low input costs -- this means you build your systems yourself with recycled materials and used equipment whenever possible. If you go out and spend lots and lots of money on pens etc, it will never be profitable. Be cheap and frugal as much as possible / and trade, barter and bargain for everything.
5. Charge enough to make a profit / good marketing / find customers willing to pay what you need without being crazy unreasonable in your pricing (you want repeat customers )
And, additional points are:
1. Raise the birds in the healthiest manner possible so as to reduce mortality. Often beginners make many mistakes and lose a huge percentage of birds. If you can label your birds "humane" or "organic" or "antibiotic-free" you can charge more for them because it's a niche.
2. Create efficient systems for your project (often beginners do things the hard way but sometimes that's how you learn. unfortunately it means you may not make any profit).
3. Track ALL your time and expenses (and feed), so you know your REAL costs. Most people are very neglectful with this and don't really know what their costs are, therefore they don't really know if they made money or not.
4. Start small. Build gradually as you learn what you are doing.
5. You must realize you are making a major commitment (being home every day, twice a day to feed the birds). No exceptions to this -- it's not like you can just go away for the evening or weekend without ensuring the birds will be fed.
6. Think seasonally -- it would be dumb to raise birds in the winter -- all that money spent on heating would cost you any profit, and likely bird health. Depending on your climate, raise birds as they are naturally raised... chicks in the spring, growth during warm seasons, butcher in fall (cool weather).
Hope this helps!