Hi and welcome to YT! You will definitely want to find a reputable breeder. I know $2000 sounds like a lot, but if you save up, you are going to do yourself a favor in the long run. If you risk getting a yorkie that costs less, you are basically going to be getting it from a non-accredited breeder and the pup may have genetic and other health issues. Those issues will end up costing you up to that $2000 or MORE anyway. So, may as well pay the money for a well-bred and HEALTHY pup. Ya know?
Here is a book that is recommended around here sometimes...Yorkshire Terriers for Dummies:
Yorkshire Terriers For Dummies: Tracy Barr, Peter...
And, here is a place to start looking to find a reputable breeder (remember, you want to shop for the breeder - not the puppy. Find the right breeder and you'll find the right puppy for you):
CYTA - Home
It is fantastic that you are researching ahead of time. Use the info that you are finding and make a well informed decision...if you do that, you'll be so happy and you'll have a healthy yorkie puppy that will give you so much love!