It takes about 16-20 lbs of feed to raise them to 5 months (depends on jumbo or normal, male or female, winter or summer) then about 12 lbs a month to sustain them. You can figure out your feed costs for however many you intend to raise. Make it easy and say 2 bags of feed per bird the first year and 3 per bird to sustain a breeder every year after that. I am betting training stock won't cover much. There's just not enough guys that buy them to warrant a very high demand within driving distance of a given area.
Of course that's purely speculation as I don't even know the current price of feed since I grow and mix my own.
Years ago when the government used to buy them for restocking it was smooth sailing. Now everybody and their brother grows them. Also every time there is a drought the grain prices go up and never fall back down the next year when the yield is normal. Even the longstanding game bird hatcheries are dropping off like flies here lately. My suggestion is to just look at it from a hobby perspective. 100 sq foot would give you room for 3 females and a male. I'm betting that
ebay for the eggs and craigslist for the eggs, chicks and adults along with a separate add emphasizing training stock would get you a whole lot closer to your goal. I'm also betting if you factor in feed, initial stock, electricity, labor, 10% mortality rate, feed waste/rodent control and misc equipment there would be no way to provide a sustainable business model at that scale.
Not trying to dissuade you as I like them myself and would own them on a very small scale if it wasn't profitable on this scale. But going in if you look at it from the hobby scale perspective any profit you make to offset the feed bill will have you that much further ahead if you enjoy raising them.
Good luck.