It doesn't exactly work like that. How a dog is raised doesn't guarantee how it will turn out. I've seen dogs in horrid condition come bre great dogs. I've seen dogs raised with every chance to succeed wash because you can't create something that's not there. Dogs that are brought up with socialization that still become fearful and nervy.... ect.you can research a breed to death and get a good idea of there temperament but it comes down to how their raised if their not properly socialized and given boundary's it doesn't matter what line they come from. Remember breeders are in it to sell puppy's their not going to advertise this is the worst behaved puppy we ever had give me $1500.00 for him
Responsible breeders still exist who breed for purpose and specific temperament, health, ect rather than "to sell puppies". I've had some very nice dogs that I didn't pay anything with. I have a couple breeder friends that never sell puppies. Not every breeder is a byb or puppy mill. I also feel that in order to get a puppy in the most suited home the breeder would need to know what the person is looking for and obviously let that person know about differences in puppies if any.