It does sound expensive, but it is a one time thing and if the Psychologist got a good "clean" test it should be a one time expense.

I had a lot of second thoughts about testing our DS when he was in his 3s (am I wasting my money? Of course he's not gifted - he seems so average etc). The money I spent on testing was some of the best money I have ever spent. I am so glad we did it - the information we got helped us so much.