Younger parakeets are often a better purchase than those that are more mature. Young parakeets are easier to hand train and are easier to teach to talk. It is possible to tell a young parakeet by the black bars that cross the feathers on its forehead. A parakeet with clear yellow or white forehead feathers is close to or at physical maturity.
Well-socialized chinchillas often make wonderful pets, particularly if they are hand tamed by the breeder. As with any animal, it is better to purchase your chinchilla from a breeder, rather than from a pet store. Some chinchilla clubs provide literature to pet shops free of charge, so that their shoppers can know how to care for their new pets.