17. Bern Mountain Dog
The Bernese mountain dog breed is a farm dog, with great strength and a larger than average size. Buying a puppy of this breed can cost you on average $800. As mentioned above, such a strong dog can be very resistant to health problems, although its size does not help much over the years and can develop elbow and hip dysplasia. Solving these problems will cost about $6,500. The half-life of this breed is 6 to 8 years.