Video is not the be all, end all - but it helps. For under $100, you will never have a 'he said, she said' moment in a traffic accident. That alone is worth the price of admission but what if you have a road rage incident? What if you stop to help someone that turns out to be a predator?
We all want to live in a world where these things don't happen. A world where everyone is honest and owns up to their bad behavior. Unfortunately, that is not reality.