I guess if you could find enough buyers for them... however, think about it- if you're producing brevis by the truckload, they'll need to be vastly popular in order to continually sell them onto LFSs. Also- you'd need to start with some brilliant adults and see if you could perfect the line a syou go along, nipping out any males/ females with bad colouring/ temperament and not breeding those ones...it's a massive thing to think about. IME, breeding one variety 'by the truckload' isnt a smart idea, you get stuck with too many fry and then you find that you're practically giving them away instead of selling them becuase the market gets flooded with individuals and no one wants them anymore. My suggestion would be to select 3-4 species and select good adults to start with and breed 3-4 species at a time, separating them into your said 10g's. This means you wont every have too many fry at any given time and you'll be producing not only one species, but a few for the clients to choose from.
I dont even know what you'd do with 75 brevis! Especially as brevis aren't really harem colonists too. Buyers are more likely to buy a pair etc- though a fish store would probably take 10 at a time. Why dont you do some research, email around your local LFSs and find out which species are in demand, and if you were to breed certain types how many they would be willing to take and at what price and how often? You might find its a massive operation that you're just not keen on.
Shellies that are typically slow growing such as ocellatus or a tang like calvus is where the money lies as they're harder to rear and it takes major patience on the breeder's side to keep the operation going. I would suggest you go with something more like either of those two, other than brevis. Anything that's bred by the truckload is likely to be recieved well at the beginning and then the interest dies off as the species floods the markets.
Good luck to you! I've always wanted to do something similar, and picked up the above tips when i looked into it

Let us know what you decide to do!