If I ever was in a business of selling dogs (which I'm not, and never will be), I wouldn't sell my pup to anyone who walks through the door and offers me money.
I would do my best to screen, question, and work with any prospective buyer. I would meet the family, find out what their plans are for the weekday care for the pup (8 hours a day in a crate just won't do), find out if they had other pets and what became of them. I would insist they make appointments with a vet and sign up for classes before they pick up the pup. I would remain with them in contact, and have it written into the purchasing contract that the pup must be returned back to me, if they realized they couldn't take care of this dog.
Why? Because I'm choosing to bring 8-12 pups into this world, who may be abused, mistreated, or turned into dangerous animals if raised without proper care. *I* would feel responsible.
There is not one single pet store that cares about any of the above. There is not one single breeder that sells pups to pet stores that cares about any of the above. That's why you shouldn't buy from pet stores. Either find ethical breeders or adopt.