I've been a chicken owner for a few years now, and I've both raised my own chicks and purchased pullets and laying hens that were coop ready. Each has its pros and cons. Buying coop ready pullets or hens that are already laying mean all the hard work has been done and you'll be getting eggs pretty quick. Raising chicks is a lot of work. They're messy and their brooder requires constant cleaning. I can't even describe to you the amount of dust they create in the weeks that they live in your home (or wherever you keep your brooder). Despite all that, my personal recommendation would be to raise your own chicks. Seriously.
I came to this conclusion last evening when I went to close up the coop for the night. As I walked out the back door, the 2 hens that I started as chicks this year (the only 2 out of the flock that I raised myself), came racing towards me. You might assume they only do this because they hope that I might have some type of food, but they do this every time. They follow me down the barn, they come running to me when they see me and they come when I call them. Not only does this make me feel loved (it doesn't take much), but it also makes it easier to check them for any signs of illness or injury. And if there is a need to treat them, it's easier to do that as well not only for me, but a little less stressful for them.
So if you're thinking of getting your own chickens, I highly recommend raising them yourself if you have the ability.