In my opinion, I think you should use the points on other things. But not because I think the BB guy is incompetent but because I think you should spend a few hundred dollars and buy your own equipment and learn how to calibrate your TV yourself. Calman 5 is a very straightforward program and the Grayscale Calibration for Dummies Guide
can walk you through a calibration. You can even download HCFR for free if I'm not mistaken which means all you'll need is a meter which can be had on the cheap. If you're dead set on a BB calibration, then go for it! I have a hard time believing that if I can use a Calman 5 and a $300 meter and get the results that I do, that even a Best Buy calibrator can't achieve the same results. He's supposed to provide you with a before and after report anyways. If the report says he didn't change anything or provide you with noticeable changes, then call the store and let them know. A DIY cal will probably not be as accurate as a guy who's been doing this sort of thing for many years day in and day out, but it will be close with a little effort. I think the same will hold true for a BB calibration. It will not be professional grade but you should have noticeable changes.