Some people want different things from a static site. Rather than charging a flat amount for a site, set yourself an hourly wage. After doing a few sites you should be able to gauge how long a site will take. Though if you want to see what other people are charging, look in the classified of your local newspaper.
Thing is with an hourly wage, something could really mess it up and you'd have to spend shitloads more time on it, and make the price unreasonable. I guess that should be taken into account in areas such as risk management, the newspaper doesn't really offer anything in this country like that, but i've been having a look around the net.
You're right that it should be taken into account as risk management.
I've done the same kind of pricing for freelance web design gigs. As a college student getting a computer art degree I charged between $10 and $20/h for my time, plus costs. As I got more experience I could get away with charging more. Often it took longer than I anticipated, but the clients I worked with were small-scale enough that they couldn't have afforded me at a realistic per-hour wage, and I needed the experience for my resume so I did the work anyway.
Part of the huge discrepancy in costs is because clients are paying for a lot more than a website. They're paying for professionalism, timely responses to emails and calls, a good understanding of what's realistic to expect a freelance designer to do (since many clients have never commissioned a website before and haven't the foggiest what kind of source material to provide), professional-looking office space for in-person meetings, transportation to on-site consultations, etc. So on the lower end you have the high school and college students doing sites as favors to entrepreneurial friends and family, and they charge next to nothing because it's all the clients can afford. And on the higher end you have pros who will do quality product photography, write good web copy, are experts at user interface design, etc.
So it all depends how you're marketing yourself. The more professional you appear, the higher-profile clients you can attract, and the more you can get away with charging for the same kind of basic site.