One of the best ways to sell large breed puppies is through a classified advertisement in a breed magazine. If that does not work, try newspaper classified ads or placing fliers at local veterinarians' offices and other dog-related businesses.
Large breed puppies come with unique challenges, so a targeted ad to people who are familiar with them is ideal. It is also important to screen buyers carefully, regardless of where you find them. Many people buy puppies on impulse and then find themselves unprepared for the challenges of raising a dog. This is especially common in large breeds due to the extra expense and the dangers that come from having a large, unruly dog. Make sure the people buying the puppies are prepared for the cost and training and do not plan to resell the puppies. Avoid dealers or pet stores because they typically do not screen their buyers. Pricing the puppies at market value may help screen out some commercial buyers.
It is also important to make sure that you are following all state and local laws. Many states do not allow puppies to be sold before they reach 8 weeks of age, and many breeders recommend keeping them until they are 12 weeks for extra socialization.