Jesus, only $500 a *year*?? May I ask where you live in? I live in MI and I pay about $990 a year for minimum liability insurance.
Here's an interesting story that gave me greater understanding of how insurance is priced. Years ago, I worked at a place where I lived 5 miles away as the crow flies. However, due to geography, the only way to get between my work and my home was by car, using one of the most dangerous freeways in my state.
I got tired of the commute and moved closer to work, close enough that I didn't have to use the freeway (or even drive unless I was lazy) anymore. I reported the change of my residence to my car insurance company, and they cut my premium by a third.
They didn't say why, but I'm certain the reason was that I didn't take that freeway 10 times per week anymore.
I do wonder if the same thing would have happened if I carried comprehensive rather than liability. I suspect not. They may see liability-only policies as an indicator that the customer is of limited means.