Steadycam
 

The cost is all relevant to the persons skill level at building such an item, not to mention their resourcefulness at obtaining the right materials for the job. If you have mechanical or engineering skills then the task is quite easy. I built one using top grade aluminium and quality gimble bearings for $60. Its one of the more basic designed units and I found, for me personally, it works no better than using my XL2 hand held. Its like anything, if you want the best then you have to pay for it.

Hi John,

If I understand you correctly, you want to put a shotgun microphone on your camera.

If this is what you want, I would say it is not a good idea.

The shotgun microphone best near mouse as close as possible, not mounting on a camera.

Regards
Leigh