Here is my view....basically the formula is not fixed for any site really because there are a few variables involved:
1. Traffic amount and type of traffic
2. Revenue site generates
3. Amount of monthly maintenance to the site
4. How much regular management is involved to run it
5. Amount of work put into creating the original site
6. are there memberships
7. How does it rank in search engines w/what keywords
8. and as others mentioned, depends on if there are buyers
The three key parts is: Traffic, Revenue, and if there is buyer interest in it in a specific time period...say, 2 months. If no one has interest for quite awhile, then the price is too high.
I've sold a couple sites in the past myself and if you take everything above in combination this will help establish it's value. Many formulas show up with people. For instance: taking in account the above 8 notes, establish what you would REALLY like to get for it, then what your minimum sell price is, add those together divide by 2 then that is your starting figure. Another as it was mentioned average out 3 months of revenue, etc...
Regardless of what method you use, in the end, its really up to "what a buyer is really willing to pay for the site" ...buyers market. As a buyer though who is being told the price is huge, I would not pay a dime until I saw proof of Search engine stats, web site stats, and of course, something in the banking financial records to show you are making money.
Anyways, good luck with it and don't buy that tropical house yet until you have the $$ in your hands
