$350-$500 to have a professional calibrate your display is a scam, pure and simple. It was worth it with CRTs but today is irrelevant for consumer televisions. Not to mention you have to get your tv re-calibrated Again for even more money after a certain amount of hours. For consumer televisions, its is simply irrelevant.
A calibration disc gets you a very accurate picture already, and you can re-calibrate your tv again in the future for no extra cost. Calibrators try to convince you its worth it simply because thats how they make their money.
Oh, so blue is 1-3% a different shade of blue than the source. On screen, It is not visible to the human eye. You know its all BS when someone needs a meter to see the difference and errors.
Don't fall for it. Save that $500+ dollars and get a better plasma and calibration disc.