Which dog should i get and how much do they go for ususally as puppies?

Please consider adopting a dog from your local shelter. Adoption usually costs less than $100 and usually you get great dogs that will love you for getting them out of that shelter. Pure bred dogs actually tend to have a lot more health problems than mixed breeds since they have often been inbred for many generations to maintain the breed characteristics. I don't know about bull mastiffs but english bulldogs tend to have skin and respiratory problems that will cost you a lot in vet bills in the long run. German sheperds often have heart problems that will also get expensive.