Here are my thoughts:
Researching the market for the Corns you'll be breeding is a good move as you're new to the reptile world.
Some Corn morphs are very much more expensive than others as they're still relatively rare and sell to specialists/other breeders. These will decrease in price pretty rapidly, as Corns mature around three years of age. If you buy hatchlings with the intention of breeding, you won't be alone. By the time your offspring hit the market, they're unlikely to be selling for anywhere near what their parents cost you. Even so, you probably won't be selling all of them locally so look into internet marketing and shipping.
Some of the cheaper Corn morphs sell better because they're cheaper and so more geared toward the pet market. You can probably sell these locally and not worry about wider advertising or shipping. However, your local market may be limited, depending on how large the population is and what other Corn breeders there are in the area.
If you have a local reptile shop (or shops) and you're confident that they are responsible, you could ask about wholesaling to them. However, this will get you significantly less per hatchling than the shop will then sell them on for. You essentially pay for the convenience of being able to sell large numbers of Corns for minimal effort on your part. Selling direct from your home can be a bit of a pain, with purchasers tramping in and out of your house if you want them to collect.
Know what you want to produce and buy breeding animals that will get you these. Falling in love with an impulse purchase at a show is very common (been there, bought the T-shirt!) but you can end up with Corns that won't fit your plans unless you're very hard-nosed.
Bear in mind that the Corn market can be volatile - there are runs of good years, but also the occasional bad year. You won't necessarily be able to sell all that you breed quickly, so be prepared for longer term housing/feeding of hatchlings, just in case. My general feeling is that the past 18 months have been quite difficult, with many people (including me) still housing/feeding hatchlings that arrived last Summer. With anything between 10-30 hatchlings from one clutch this can be a drain on finances, so keep a bit of money set aside just in case.
A pool of savings will also help with potential vet bills, as in my experience, breeding has been the single biggest reason for my vet visits.
Blimey - this makes breeding sound like a bit of a disaster area! Sorry, I didn't mean it to. However, these are all points worth mulling over as you're doing your research.
Good luck!
