Even if you have agreements in place with local pet stores, they don't always hold up.
Yup, I've had that happen. I usually sell all of mine to my local reptile shop and on two occasions over the years they weren't able to take the hatchlings but could only tell me AFTER the eggs had hatched. One one occasion the pet reptile market pretty much stopped after a press scare on salmonella, and the second time, one of their bulk customers decided to breed their own Corns without telling anyone in advance.
If you're going to sell locally to individual buyers, then it very much depends what's already available. You might want to keep an eye on what morphs your local shop is breeding and make sure that you're producing something different. You might also want to look at their prices and think about whether you'll be undercutting them and so potentially souring your relationship with them as a customer.
Also, when selling direct you'll have strangers in and out of your house to look at the snakes. And you need to be prepared to refuse a sale if someone seems really unsuitable as an owner.
You might be able to set yourself up with a FedEx business account so you can sell further afield, over the internet, but that in itself isn't an easy process (the Search function should throw you up a few threads on shipping).
It has to be said that the first season of breeding, you usually don't cover your costs. You'll have to buy housing, heating, stats and food for, say, 10 hatchlings per clutch if it's a first clutch (more if the snakes are older).
That all sounds really negative - sorry! However, it's best to be aware of potential pitfalls and props to you for thinking ahead. If you can get all the ducks in a row, then it's an amazing process.