Same as Caroline1 - I don't really make any money when I raise batches of chicks from eggs.
If they are my own birds eggs, I same the £40 outlay on buying eggs in, so that's a bit of margin. If I give them some grain, once they're up and growing and that maybe saves another £10 to add to kitty.
But for me to grow say 15 pullets from eggs for 4 months, £50 is nice, but not really "making money" if you know what I mean. I normally do about 2 or 3 batches a year. Not even started yet! And sell eggs to friends, so I'm quite happy that the hens pay for themselves, and probably keep the dog fed as well.
If I were to put on a batch every three weeks, it would start to mount up, but that would be a lot of heat lamps, feeders, pens, houses, hassle, etc, as well as too much risk of a disease outbreak or even a predator killing the lot and costing me a lot of money.