Broiler chickens aren't in cages like battery hens (IIRC the point of the cages was to make egg collection easier), they're in a big shed, but it's not a lot better. I am sure you can find lots of gory details of chickens spending their whole lives living in their own excrement and getting ammonia burns from it, which may put your dh off his standard cheapo chicken.
If you're a lapsing veggie you might find this book of interest (if you can get it cheaper!)
The River Cottage website (rivercottage.net I think) has lots of info too.
You will find that supermarkets put more of a premium on free range than butchers do, so a butcher might well work out cheaper. However, you might need to bite the bullet of being prepared to use the whole chicken rather than just buying breasts. (You could always buy a chicken and joint it so you have 2 breasts, 2 wings, 2 thighs and 2 drumsticks, which you can stick in the freezer, plus the rest of the carcass for stock.)
When it comes to free range, this can cover an enormous range of standards of welfare, from farms which give the birds the absolute minimum required by the rules - eg in theory they have access to space outside but in practice there are so many birds that most of them never even get near the exit - to some which are almost organic in all but name. A supermarket will not be able to give you further details of what you are buying but a butcher might. If you buy from a proper farmers' market it will be the actual producer on the stall so they can tell you anything you need to know. (We had a yummy 'proper' free range chicken from Loose Birds of Harome at the w/e - £7, compared with £10 for the organic ones we'd been buying. When you think we'll have got a total of over 8 portions out of this (roast chicken, salad, sandwich, stock for risotto, plus extra of each for our toddler) the price actually looks pretty good, especially compared with readymeals.
Good luck & happy yummy happy chicken eating!