I agree that the large pet shop chains do buy from a mass production supplier unfortunately this can mean that they are not bred for temperament or health and are generally prone to a common lung disorder. i like many have learnt the hard way with buying from these stores. However when i used to breed for show i bred for temperament and health if they couldn't be handled they couldn't be shown. I also took into consideration what mass breeding can do to the females that i still wanted to show. My females never had a litter until they were 6mths old and i never let them have more than 2 litters in their lifespan. My babies were handled from 2 days old i never had one with a nasty bone in its body. Whatever wasn't show standard of my litter eg markings or colour were incorrect i would advertise and sell my self while also selling to a local shop who knew my reputation for the rats i turned out. Sometimes best to buy privately when you can see the parents and how they're kept, just as you would a dog, or from a small local store that possibly know where they came from and/or can give you some background.