do a search on YT, there are a few threads about parti colored yorkies.
I bought Nigel from a breeder in Louisiana that I found online. She has plenty of references and her dogs have champion lines.. I also found her prices to be reasonable. If I tried to buy one here in NYC, I would be in the poor house. Rates average around 1800. I knew I would have to go out of state. Nigel was shipped, and he came healthy and is adjusting well in his new home with moi!
There are scams out there, and I think they are pretty obvious for the most part. See if you can get vet references from them and make sure there are pictures of the parents and that they can be reached easily by phone.