Mom2R&R,
Our DS took the WISC when he was 6 as part of the admission process at a local gifted private school. It's proved to be far more helpful that just for that purpose, however, as it gave us a clue about his strengths and weaknesses (and also indicated to us his level of giftedness, which was much higher than we were expecting). That's helped us shape an education plan for him.
What kind of testing would be included in that price tag? I ask because that seems very steep to me, unless perhaps there is both ability and achievement administered.
