I would not purchase a dog off this site. They are way overpriced. A chihuahua should cost no more than $500-$600. and the higher priced ones should be able to be registered, but that even doesn't always mean anything and CKC registered means nothing.
It's best to find a chihuahua club in your area that can give you a personal recommendation. The breeders who use the word teacup are the worst as there are no teacup chihuahuas. They are from 2-6 pounds to meet the standard of what they should be. A smaller one should not cost more. It's just a scam. There is no such thing as a teacup breed. A chihuahua is a chihuahua. If you go to a dog show, you will not see a teacup category.
These internet people can be running puppymills which means they raise a ton of puppies with no regard to the quality or health of the puppy and there is no way for you to tell. They love to ship them so you never see their home or the parents which can tell you a lot about how the puppy will be. You can get what seems like a healty puppy because illnesses like heart problems and knee problems show themselve much later in life and treating these problems and others are extremely costly.
Bye, Chilidog