A good quality pet Yorkie should not cost more than $1500. Those sites are rip off sites and usually are put together by owners of puppy mills and their brokers. I hope your friend will get pointed in the right direction. Have her find a good AKC breed or conformation club in her area. Sometimes the YTCA does not answer people as quickly as they would like. They can also go to reputable cubs in their area. You can do a search here:
American Kennel Club - Club Search and Directory
If there is no local Yorkshire Terrier club in your her area then a conformation club will most likely have some Yorkie members. These clubs have breeder referral contact persons that can point her in the right direction.
Finding a reputable breeder is not always as simple as finding these puppy mills but they are worth the time and trouble of looking.