Love my PV500.
It paid for itself by the middle of the third shop I did with it, and it continues to generate good income. I only do video shops that are over $200, or $250 for EPMS because their reporting experience is so awful.
Only issue I see with buying used is older versions are not as slick as the current NeoPro.
It has a screw-on collar connection for the cam to the camera that is totally solid, and the mic is now in the button. The older ones I borrowed from EPMS had a separate mic that had to be attached with a safety pin.
Have synthesizers, will travel...