don't get chickens! lol! Seriously, they'll always be the most expensive eggs you'll ever eat. As far as how to make them cheaper here we go:
Buy locally, with no concern for breed
shipping costs a fortune, but if you want 3 Salmon Faverolles, 2 GLWs, 4 Ameraucanas and 1 Welsummer then you're going to have to pay for what you want. However if you go into this saying "I want a dual purpose brown egg layer" and that's your only criteria, then you can probably find some Red Sex Links on CL for cheaper than ordering from My Pet Chicken or any # of hatcheries. Also; if you can, get a rooster and you'll hopefully never have to buy baby chicks again.
Only buy what you need
Family of 4? you only need about 3-6 chickens. While in the summer you'll have a lot extra you can sell to family and friends, remember that once winter hits you won't be getting 3-6 eggs per day. My suggestion: freeze extra eggs for winter months. I freeze mine 2 dozen at a time by straining them through cheesecloth into a gallon freezer bag. I freeze mine flat so they stack easily. Freezing them for winter use saves you from having to buy them.
section 8 coops
That's what I like to call my "I have a low income" housing for my chickens. All of my chickens from this spring onward (and turkeys and ducks) are being put into hoop houses. Hoop houses are just one of a variety of inexpensive housing ideas. Generally speaking you can have cheap chickens or you can have a pretty coop. Unless you have lots of building materials already on hand, the coop is going to be the most expensive part of having chickens. If you have to have a pretty coop, you're just going to have to bite the bullet and fork over the cash to build (or purchase) an attractive coop. Otherwise housing for chickens can be made out of pretty much anything. Also remember, if you're fencing in a run chicken wire or hardware cloth isn't cheap. If you can free range your birds, that'll cut down fencing costs.
time of year
I get my first batches of chickens in April or May (last batch in October). Why? because I don't want them in my house. chickens under heat lamps stink to high heaven. they have a not-so-faint aura of microwaved Velveeta cheese no matter how clean I keep their bedding. I get my chicks and they stay inside for about 3 weeks under heat then they go outside with heat only at night for a couple weeks before I turn it off completely. (keep in mind that their brooder only starts off at about 80 degrees) This means that while most people are running heat lamps for 8-12 weeks in February I only run mine for about 4 1/2 weeks in late spring, early summer. Saves on electricity and I haven't lost a chick yet due to weather
Feed
I grow all my own veg from seed. Being that it's just my husband and myself I end up with many, many more plants than we need. Every year I plant a big garden for us and a big "chicken garden" for the gals. It costs me no more to provide fresh fruit and veg specifically for the chickens and it means that their feed costs are less in summer/fall. I also save kitchen scraps to give them daily and sometimes when I'm feeling generous I'll buy a bag of crickets or nightcrawlers for them. In the winter they get regular old feed with kitchen scraps. Free ranging them also is a great feed supplement as long as they always have access to good greens.
Eat them
Don't let excess roos become a problem and certainly don't keep feeding lazy hens. Say you have 6 hens and a roo and it's November and they're production is coming to a grinding halt, don't feel obligated to keep feeding them. Let them feed you. You can knock off 3 or 4 hens for winter and come spring have some darling chicken nuggets (baby chicks) to replace them.
Of course you may not want to eat your chickens, you may never have a rooster and you may have a solar powered coop whose exterior looks and interior features rival that of your neighbors homes, so take from this what you can and remember; while it's cheaper to have no chickens at all, it's not nearly as much fun!
edited for clarification and grammar