PET SHOPS
Do they in general have any knowledge of chinchilla keeping? Obviously not, the only way to learn about chinchilla keeping is to do it and that does not mean putting one in a cage on sale to the public! You cannot learn about chinchillas from books either most of the pet books on sale in the UK are downright rubbish! What about the background of the chinchillas they sell?
They are in general not interested, they will offer a minimum price to anyone offering chinchillas for sale, usually about £15.
perhaps £20. if they are desperate, and have no interest in the background of the chinchillas, its quite unusual that they should ask the age, very often I hear of people buying chinchillas in pet shops at around 7, 8, or 9 weeks old, this highlights the shops lack of knowledge, they have not even bothered to research how old chinchillas should be before being sold!
Chinchillas of course should not be weaned until around 8 weeks old then given at least another 4 weeks to make sure they are eating and drinking and looking after themselves before being sold, its quite a stressful time when they are weaned off.
Pricewise can you really expect a good deal from a middleman who has to put his profit (Usually around 200%)  on top of the price he pays to a supplier?  We wont go into cage and equipment prices here, I would just say quite often cages are offered by pet shops that are totally unsuitable for chinchillas. If you are lucky you may find a pet shop that can show you how to sex chinchillas correctly!

CHINCHILLA KEEPER WHO BREEDS A SMALL NUMBER OF PET CHINCHILLAS
Usually enthusiastic pet keepers do over time (at least 5 years) build up a certain amount of knowledge on chinchilla husbandry. The problem is that unless they keep a reasonable number of animals their capacity for learning about genetic and other problems is limited. They are also restricted in their selection of future breeding stock by the limited amount of offspring produced.

RESCUE CENTRES
First a word about rescue centres, many I am sure are set up with the correct intentions and the welfare of animals put as a first priority but at least as many are set up by small breeders when they realize the profit potential and in many cases free advertising thrown in!------but regardless of all that we are looking for the best place to buy your pet chinchilla!
Rescue centres are no different than pet shops in that in the majority of cases they have no idea of the background of the animals, now I know that these chinchillas still need looking after but I have seen too many times the heartbreak caused by purchasing a chinchilla from one of these rescue centres and having it die in great pain from teeth problems within a couple of years.
Please note; Above by no means applies to all rescue centres, there are a number of genuine rescue centres with a good knowledge of chinchillas who actually advise against breeding with stock from themselves due to uncertainty about the background of the animals.

ESTABLISHED SHOW OR PET BREEDER
The established breeder of large numbers (50+) of chinchillas, whether for pet or show, is in the enviable position of having enough stock and producing enough offspring to be able to select his future breeding stock from his healthiest animals.
The show or exhibition breeder is usually especially careful about choosing his future breeding stock, it can take many years of hard work to produce top quality show animals on a regular basis, the last thing such a breeder wants is to have this work wasted by the appearance of genetic health problems. When I first started breeding in 1988 there were many such problems
with my original breeding stock---teeth problems---breeding problems---temperament problems,  all these have been selected against to a negligable level---but not totally eliminated, selection against defects is an ongoing task