Thanks everyone for the replies! You guys are so helpful

I see both sides of people telling me its a good buy, and to watch out.
Anyways, my mother is a nurse, and one of her patients (she visits them at home) dog's had puppies--its no yorkie

Its some kind of mix...And they agreed to give us one, a sort of thank you to my mom for caring for the patient and their family, I'm excited about that, but I still want a yorkie
So I don't really know what dog I'm taking home yet...
After reading the replies I'm definately going make sure that if I do get the yorkie I'll have all my research and what not, and make sure this is the puppy I really want. I plan on visiting the breeders' home hopefully sometime in the next couple of weeks.
--Ashley