It's a numbers game. Years ago I used to breed and sell 50,000 fish a year. Sold mainly to one wholesaler. If you want to do it economically you have to breed a lot, then you have to sell a lot at a price that is better than a wholesaler can get them overseas and have them available when they want them and not when they have enough. It's a lot of fun but I wouldn't dream about getting rich and famous. You cannot sell at the back door if you want wholesalers to buy in quantities. Please keep your day job.