Emily at the Cozy Inn Pet Resort and Spa in Plum grooms Max and Abbie. She does a FABULOUS job with them. She's been grooming them for years. It's kind of out of the way for me but she's worth it (after the bad experiences I had with Petsmart and Petco.) I believe it's $32 for a full service groom for a yorkie.
check out the website (it's also a boarding facility):
www.cozyinnpetresort.com
(412) 798-5297