The rates that were quoted for us were $700 for each our children using our local well known and well recommended tester. I believe she is totally worth the money, but I didn't have 1400 dollars.
I was quoted 800 per child to have the testing done at Dr. Silverman's clinic in Colorado, plus the preconsultation at 125 an hour, and by the time I would add in travel cost we would be talking real money.
That said, I think the cost of testers who work with gifted children would be totally worth the money, especially after the first experience.