Just FYI, there is no such thing as a "teacup" yorkie. (YT won't even allow the term to be used here when listing puppies for sale.) It's a very misleading term used for marketing by unethical breeders. If you run across someone advertising or claiming to have 'teacups', run the other way...FAST!

I would suggest that you research the breed before deciding on a pup so that you can be better educated about what 'scams' you could encounter and what some of the common red flags amongst Yorkie breeders are so that you can better avoid falling victim to someone out to make a quick buck off of you and breeding dogs for the wrong reasons.
Good luck and welcome to YT!