
Hi Pam....Welcome to Yorkie Talk!
Here is a link to the AKC Yorkshire Breed Standard which states that Yorkie should not be over 7 pounds at maturity.
http://www.akc.org/breeds/recbreeds/york.cfm
Many pups do grow to be larger, but most stay under 10 pounds. The vet feels that my own Higgins will probably top out around 8 pounds when he is fully matured.
Higgins weighed 1.5 lbs at 8 weeks old. In my opinion (and I'm NOT an expert), a puppy that weighs 3 pounds at 8 weeks will probably grow to over 10 pounds at maturity. Could this pup possibly be a Silky Terrier? They are larger dogs than Yorkies, look very similar, and many breeders breed both breeds....so accidents happen. Iif you are being asked to pay a steep price for a top quality Yorkie, I would be wary about buying this pup.
Hey, in the final analysis, if this pup has captured your heart and he is healthy and reasonably priced, then welcome him into your family. We knew that our Higgins was strictly pet quality who would probably not meet the breed standard, but since we were not breeding or showing, we opted for just having that great Yorkshire personality -- willful and delightfully rebellious.