Longshot has given you some excellent advice there. My husband surprised me with my pup and I had no say in where he came from. My pup was full of worms which required medicine and required an additional round of shots that would have been taken care of by his breeder because he would not have come home so early. In addition I had him cropped by a crop artist and had his tail fixed at the same time which cost me $485. So by the time we had taken care of the health issues he came with and had him cropped it was almost $1500 including the price of the crop. I also had to deal with healing ears which is not something I ever hope to do again. If you buy a pup from a reputable breeder you will get your pup after the initial healing is done and you'll only need to worry about posting.
This breed suffers from some horrible diseases and if you buy from an ethical breeder they will health test the parents and they will know their lines, the health issues and longevity of the lines as well as the temperament of the parents. A reputable breeder will only breed with a distinct purpose in mind for that breeding and will be able to tell you what they hope to accomplish with each particular breeding. A person with pet dobermans that breed them together do nothing to add to the breed. They will tell you they're not breeding "show" dogs but quality family pets. They will not do the appropriate health testing and you may get yourself a ticking time bomb like I have as you will never know if your pet inherited a disease that you won't find out about until it's too late.
Things to look for are a breeder that breeds 1-2 litters a year, does the full health testing (DCM which includes a DNA test as well as getting yearly echos and holters to determine the health of the heart, CERF for eye abnormalities, liver panels, thyroid, OFA for hips and elbows, and vWD). DCM is a horrific disease that kills so so many of the dogs in this breed. No line is completely free of cardio issues but a good breeder that knows their lines will do everything in their power to breed for health and longevity.
A good breeder will also send you home with a crop that is already healed and give you support throughout the process in order to give you the best chance of success. They will support you for the life of your pet and if your life circumstances should change they will take that dog back and do their level best to find it an excellent home. A good breeder is there for you for the life of the dog as they will take responsibility for that dog for its entire life.
You want to make sure the parents of the pet are titled either in show or sport to ensure that the dog you get is representative of the breed in that they are capable of doing what a doberman was bred to do and that they have the correct temperament for the breed. There are almost always pet quality dogs in a show/working litter and your breeder can match you with a puppy that will be an excellent fit for your family as they will know the drives and individual personalities of each of their puppies.
Hope this helps you make the decision to go with a reputable breeder. I'm sure I left out some benefits but someone will chime in if I forgot something!