You can cut costs a lot by improvising. For a brooder, we used a bathtub in a bathroom that we never use. just put some old sheets in the bottom and put wood chips over the sheets. Easily holds 20 chicks and it is easy to feed them and easy to clean up. Plus the bathroom is already heated, so you only need a minimum from a heat lamp. Turn the exhaust fan on to drown out any unwanted cheeping and vent any odor. You will need to clean it out once in a while.
For a heat lamp both in the brooder (bath tub) and in the coop, just buy one of those clamp on lights you can get at a hardware store for $5. Put a 100 watt bulb in it. Position it so the chicks (chickens) and move closer or further away as they desire for warmth. They will self regulate the temperature.
Be careful with food and water dishes for chicks. they will drown in a regular bowl of water and they will poop in the food if it is open. Chicks are incredibly stupid.
Buy three of each individual hen that you want. You will get stuck with some roosters and have to get rid of most. (we generally keep one or two that we like the best because they control the hens, help them find food and protect them). The remaining roosters can be taken to a processing place, or just take it to your local shop and ask them to put them out for free (we drop them off at
Tractor Supply Hardware - they put them out for free and someone always takes them in a day or two). Some of the chicks will die. They just do, some will be roosters. Some will likely get killed in their first year either by predators or by doing something incredibly stupid. Usually after a year, we end up with about a third of the number of chicks we buy. Thus we buy three of each. Oddly when we buy ducklings, they all seem to live (although they flew away with the wild mallards in the fall of the second year).
You do not really have to buy a lot of food. The can eat bugs, grass weeds etc. When they are out, I turn over logs so they can eat the bugs grubs and worms. When I cut grass, I throw some in the run, when I pull weeds, they get the weeds. When we have a barbeque or any meal they get the left over or unwanted foods (they love salmon skin). Be sure to give them left over egg shells (we rinse them off first). In the winter, you need a floating heater to keep their water from freezing. You may need another light int he coop, especially if the coop is not insulated.
We build the coop out of left over lumber. The only cost was some hardware we did not already have. We painted the outside with left over paint. The coop cost about $12 to build. I easily and safely holds 15 chickens.
For use the biggest cost was building the run. You need a large area and it must be built like fort knox. The wire needs to be embedded into concrete at least 6" deep. You need to cover the top with chicken wire as well as all sides (hawks, eagles kestrels owls, etc). The gate must have a complex lock. Raccoons love to kill chickens and they are very clever. We also learned the hard way, not to use the 1.5" x 3" wire fence like you use for horse pens. Young chickens can wiggle through the holes and raccoons will reach through and pull the head off adults. You need the regular chicken wire at least around the bottom. We put chicken wire over the horse type fence which is much more rigid and stronger than chicken wire.
If you free range, you are probably going to lose some chickens from time to time. Some dogs can learn to watch the flock and protect them. If you see hawks or eagles circling shoot up a bottle rocket and they will go away. Do not let them out on windy days. We had one chicken simply blow away in the wind and we could not catch up to her (poor thing).
You learn to be a better chicken keeper from experience. You will lose some from time to time, try not to let it make you sad. Some will survive for years and years, but some always die.
If you decide to try to hatch eggs, do not get a cheap incubator. Get a good one and make sure it has an automatic turner. Keep the humidity up, if it dries out they will not hatch. I also would not recommend an incubator made of styrofoam. They break too easily. We gave up in incubating eggs. It is cheaper to just buy chicks if you need more.
Buy your food at a farm supply store, not at a pet store. Do not use wild bird seed. Wild bird seed often sits around for months or even years and it often contain mold or other things toxic to birds. If your wild food kills wild birds, you never know it, but if it kills your chickens, you will be sad. We have yet to find anything chickens will not eat. If it grows, they will eat it. They will also eat pretty much all meats, bugs, worms, etc. I suspect they could live on just your leftovers, but we give them some cracked corn as well as their normal bugs, ants, grubs, worms, grass and weeds. If you have yellow jacket traps, dump the dead yellow jackets out for them to eat, they love them!
Big chickens (like Jersy Giants) mixed with little chickens (Banthams) can be disastrous. They can just step on them or jump and land on them by accident. If the big chicken is a rooster, he can kill a Bantham just trying to mate them.
Ducks mix with chickens just fine. Sometime the duck thinks it is a chicken. That is fine. It can be a problem if a chicken starts thinking it is a duck (chickens cannot swim).
This is a really fun hobby and chickens each have unique personalities. They are a blast. It is surprising what neat pets they make.
The cost is probably not balanced by the egg value unless you have a ton of chickens. The neat things about it is you are never out of eggs and you know the eggs are always truly organic, free range and free of chemicals. Neighbors may stop by when the run out of eggs. With Easter Eggers, you can bring blue and green eggs to work once in a while and amaze everyone. Duck eggs are unique. They are super rich and have a slightly different taste (I like them better). Chickens eliminated our ant infestation problem and the keep grubs, snakes, and other pests down too. Plus they are just fun to sit and watch them interact, or to pet or play with.