robho - 3:50 am on Dec 5, 2011 (gmt 0)
I assume you're looking at buying it (if you were selling, you'd have some internal figures such as unique visitors and pageviews per month, rather than external rankings).
Revenue may creep into the six-figure range this year, but that does not take into account the fact that nobody is currently paid for services
You've hit on the main problem there. It's what Dragon's Den / Shark Tank would call a "lifestyle business" that earns enough for one person or family to live on, possibly quite well, but doesn't really have anything left for investors (such as yourself).
One way to calculate a value would be to take the current annual revenue, deduct all costs including hosting AND hiring somebody skilled to run it, and see if there's any net profit. If there is, multiply that by a low figure (if the traffic and income is risky, which it is) or a higher figure (if the income is secure, which is rare). That's your price.
If you can see a way to increase revenue or reduce costs (hard to see where in this case), you can adjust the price accordingly.
Maybe the domain name is great also, could be worth buying just for that then redevelop the site with something more automated, but not many names are worth more than a few tens of thousands of dollars.