In general, it is ill advised to purchase a puppy over the internet. Often, professional looking webpages are simply fronting substandard breeders. It is best, if purchasing a pet animal, to try to buy locally from a breeder who is affiliated with a recognized breed club, such as the Miniature Schnauzer Club of Canada or The American Miniature Schnauzer Club.
Seek references, take your time and DO use the internet as a source for information - but beware! For every reputable and knowledgable dog breeder out there, are about twenty who are decidely not.
Take your time to research and evaluate both the breed and the breeders you consider. The majority of good breeders will require that you reserve in advance, as their animals are in high demand.