It's a lot of power for the money for sure, don't be too impressed by the power, I have a bike light that is the same amount of light, and one that is quite a bit more light, that I use all the time. My bike light is much more noticeable to a motorist because of the wide beam pattern created by the lens. More like a flood light. That $5 spotlight will not appear too blinding to a driver because the lens focuses the light into a tiny spot.
The problem with that thing is that it is a spotlight. It's a little less power than a car headlight, but it is a narrow beam to focus the light on something farther away than a car headlight. So you can pick out a mooring float, or a house number at a long distance. It's not a good lens type for bike riding.

By all means give it a try, at that price you could just throw it away, or use four of them. You can ride with it all you want, it will work, I'm just saying it's a very narrow beam and not amazingly powerful. And a short run time for some riders. But for $5 it does not matter. Put three on your bike !