As for price, there is usually a 'going rate' for registered good quality puppies, probably around the £550 - £700 mark, and anything less than this you have to ask yourself why. After the expenses involved it is a reasonable price, there is the cost of the stud (many breeders don't own their own stud dog and will use a suitable male that complements their bitch, or one that has done a lot of winning), the feeding of the bitch with good quality food and the rearing of the pups again with good food. If the owner shows their dogs then that is a big expense but gives you some idea of the quality of the dogs they breed if they have done some winning. Most breeders will be delighted to explain the background of their pups to you, and would ask many questions. Have a look at some Shih Tzu breeders on Champdogs too, there are a lot of good ones on there.