@teecee Honestly, I would not recommend it for a few reasons. Genetic health testing the puppy for future breeding is a good start, but buying a dog without tested parents is a huge risk (What if the dog develops hip dysplasia at age 1 because the parents had hip issues, unknown because of a lack of testing? Are you willing to lose the entire cost of the dog in addition to her future vet bills, or will you breed the dog to break even and produce more unhealthy puppies?). It's just too much of a risk in my opinion, in addition to financially rewarding unethical breeders of a breed with certain known genetic health problems. That's just my opinion, knowing that there are much better Rottie breeders out there where you could get a puppy.
This guide was written by a boarded reproductive veterinarian about reputable breeding. It's aimed at puppy-buyers, but it includes information on what makes a reputable breeder. It might provide some insight on traits that make a breeder reputable (both while you consider purchasing this dog from a backyard breeder and in your future breeding endeavors).
ETA: It looks like you've been jumping back and forth quite a bit between Rotties and Corsos. I would definitely decide quite firmly between the breeds and conduct LOTS of research before considering breeding - let alone purchasing a dog to breed with. One of my mentors told me the best rule of thumb is, "if you can't tell me the key points of your breed's conformational standards from memory, you are not ready to be producing within that breed". I like that rule quite a bit, lol.
