I bought Angel from a lady that was a vet tech for 15 years. Her daughter was my best friend and I was living in their home for 4 years and was 17. being young and not knowing what I know now, I did know dog behaviour well but that was about it. She bred her highly aggressive Red Chow female every other cycle and her Mild mannered White American Eskimo everyother cycle. The stud for both was her Mild mannered but hyper Male White eskimo.
Her reasoning was that the females needed a break but she couldnt break from the income so she bred the Chow inbetween while the female White Eskimoe took her breaks. I was told the whites never had papers because White eskimoes were not recognised by AKC then. When she through a black she was going to let Angel die because of color and illness. I freaked. She said if I could keep her alive she was mine for 50 bucks. I took on that challenge.
So Angel was bought straight out of ignorance. I was young and thought a vet tech would know what she was doing.......
Angel died just short of her 18th birthday and never had seriouse health issues but Im very lucky we managed her temperament ,It was not the best in unknown situations.
Nicki and smokey my Pomeranians, One pure bred and one not but Both AKC registered were bought for me by family members. Again ignorance but sweet thoughts behind the gifts. Nicki is still with us at 14. Both cost 600 each.....

remember that was 15 years ago. A lot of money for mutts.....:D Nicki is a weaknerved spaz but we love her....LOL! Smokey was a very stable In my opinion, Pomeranian and we were actaully going to try the show thing with him but he never dropped his other ball....LOL!
Psyche was given to us, not as a gift, not even because we were looking, Because I saw her, the situation she was in and I wanted her, asked for her and left with her. Her owner is the type that somewhat cares for his dogs but holds the old dogs are dogs and they have sex......

He wanted a pup with the lines that Grandma and Ma had. I "think" he paid a Grand for the Grandma, AKC papered purebred but I'm not for sure on the price. He later dumped the 2 dogs he kept from the litter. He has had 4 mixed litters not Rott since......:( I even offered to take the dogs in and pay myself to have them all fixed. It was a no go. He use to breed AKC registered dobermans and as far as I know he charged 600 a pup. Again not positive on that. Just trying to remember from conversations we have had.
I think most people buy from BYB's just because they don't know better or know about the problems out there. I do know that most reputable breeders I have met make little if any money.