Welcome to the forum and so glad you came here for info before you started up a new business!
The type of breeders we support here are 'responsible' breeders (click here for what that is
---> How to find a puppy!
) and generally they don't really make much money.
If you've had a chance to wander around the site, have you seen --> GSD Rescue Information - German Shepherd Dog Forums
and clicked to see the HUNDREDS of purebred GSD's posted there?
Many who were in kill shelters and are dead now?
Point being, there are sadly already too many GSD breeders just breeding and selling puppies. With no care or concern where they end up after the check is cashed by the breeder.
Instead, 'responsible' breeders do everything they can do to assure they don't contribute to that. They tattoo and microchip the puppies before they are sold so they can always be contacted if dog is lost. They spend HOURS interviewing and matching owners with each puppy (and telling people NO I think my pups are not a good match for you, thanks). They keep track of us FOR THE LIFE OF OUR DOGS to make sure the health and temperament is what they want in their program and making adjustments constantly based on feedback and the knowledge they gain with each and every litter.
Additionally, the puppy agreement says they will always take a pup/dog back at any time and any age. So the more puppies you breed the more may end up back at the kennel.
Best thing to do is locate a great breeder in your area (RESPONSIBLE BREEDER) and apprentice from them. Some of the time combining a few litters a year with becoming a good dog trainer/teacher works out well. So the classes/training can supplement the budget.
If you go up to the top of the page and in the narrow black stripe along the top, click on the User CP and put your GENERAL LOCATION, there may be breeders in your area you can meet up with and chat to see if it's really what you want to do.