If you are looking for a stockdog it is extremely important that both parents and all grandparents are working stockdogs. If at all possible, see the dogs work or see video or pictures of the dogs working. No one can look at the puppy and see the inherited ability to work stock, and it will quickly be lost by breeding individuals who may not have the intense instinct required of a working dog. Ask for a written guarantee that the puppy will work livestock if buying the puppy for that purpose. Breeders often have older puppies and adults for sale.
Many factors play into the sale of puppies and why a breeder has kept one or more for a longer time.
Although a puppy is usually its cutest at eight weeks, it won't stay that way very long. They soon progress to the leggy, awkward age and go through all the stages of young animals growing up. Puppies a little older are often easier to housebreak as they do not need to go outside as often. Although they may not be as fuzzy and cute, there are some advantages to buying an older puppy. The older puppy or dog may take a little longer to get used to you and his new home since a tiny puppy isn't as concerned with his surroundings.