I haven't read every response but for me, well, actually I grew up in a family that kept poultry so the idea was nothing new to me but I went years as an adult without them. A few years ago I started back into it for much the same reasons you stated in your original post - better quality eggs for my family. Initially, my goal was that they would pay for themselves. I downloaded Steve's Chicken Tracker (I can give you the link if you need it) and entered EVERY expense into it. For that reason I tried to keep my startup costs really low. I got a coop for free off freecycle and made my own feeder and waterer, that cost me a total of a buck for both (see my page for details). I entered all other costs - the first chicks, feed etc into the tracker and it calculated my monthly as well as annual expenditures.
The tracker also tracks income. So, the following year when my chicks started laying and I had a few excess, I sold the eggs to local people, and by the end of year two, was pleased to be able to record a monthly income of $3. That doesn't sound like much BUT - it was after all expenses AND, my family's eggs were free.
Somewhere along the way though, they became a hobby about which I am passionate more than just a dispassionate way to feed my family better. I find the personalities charming, their antics entertaining, the sounds they make soothing, and the sight of them free-ranging my backyard calm-inducing. I love having an outlet for all my leftovers, the great, free fertilizer for my vegie garden, the hard-working little tillers (i.e. over the winter they till and fertilize my garden to ready it for spring planting). And of course I love collecting eggs. I get great pleasure out of breaking open an egg and seeing that gorgeous orange yolk and know exactly what went into making it.
DH and I have just purchased 10 acres and my desire to increase my flock paid a large part in that decision making process. By the time I build a LARGE coop, and add to my flock this year, no, there is no way I will probably EVER recoup my expenses. But my outlook has changed. Now I am not just looking at it as a way to feed my family, but as a hobby. I've had a lot of hobbies over the years and every one of them has cost a significant amount to maintain so - I now approach it from the point of view that this is a hobby and I am willing to spend money on my hobby.