http://www.davidsongifted.org/db/browse_resources_171.aspx
Dr. Amend in Kentucky 

http://giftedhomeschoolers.org/professionals.html
Aimee Yermish
Massachusetts 

http://www.gifteddevelopment.com/
Gifted development center
Linda Silverman 

http://www.hoagiesgifted.org/psychologists.htm
Here's a list by state on hoagies.
(scroll down)

Prices depend on where you go and what test you need and even on if you want professional advice or just test results. 

The drs listed above keep getting mentioned  by name by other posters who say good things about them.  

Youth lives by personality, age lives by calculation. -- Aristotle on a calendar