I breed birds, & between costs for their food, hand feeding formula & supplies, cages, toys, brooders, vet appointments, & everything else, u do not really make much of a profit in the long run. It is more just something u really like to do. Not to mention the immense amount of personal time that has to go into it all to come out with happy, healthy well adjusted birds. No one is going to want to buy an unsocialized, mean, parrot.
You should not start just breeding a set number of birds to try & make money. You should find a species u like, & have had as a pet, THEN think about breeding if u can actually make the commitment in both time & money, r willing to have the birds checked by a vet, & r willing to find the best possible homes for ur birds, & be willing to keep the ones u can not sell. There is always a clutch that for whatever reason does not sell as fast, or for whatever reason ends up staying with u longer.