I think I will use some eggs from my flock and sell them as mixed breeds. I will have to buy some eggs form other people though if I want pure breeds. I only pure breed I will have is RIR, and I would have to watch the RIR lay the egg to know that that was a RIR.
I think that's a bad plan and will be hard to sell. For example, my TSC was selling chicks this last month for $0.50/each because they weren't selling and they were leghorns and australorps and red sexlinks - well established breeds and varieties.
You're bringing lives into the world. You're responsible for them. Are you willing to SPEND money on these chicks or looking to MAKE money? Because if you just wanna hatch for fun and make back some of the costs you might be able to. If you're looking to make money, you need to have a good reason for people to buy your chicks.
If you hatch chicks you will have to cull. If for no other reason than you're going to get one or two who have a failure to thrive and nobody wants a sick chick. I brought home a TSC chick with defects *for free* last week and I'm already thinking about culling it because it's not growing properly and that's a big indicator of suffering.