With calculating all cost and earnings. Like cost of development and seo you have paid plus earnings you are getting from it.
I'd basically look at the domain name, the age of the site, the content (whether its unique or not), the marketability (sp?) as to whether the site theme is profitable or not...and then you add the amount you've spent and the SEO you've done. basically if you have something unique in a market that's profitable...it's a gold mine IMO
You could always just auction it off. Post auctions on forums such as DP, WHT, Webmaster-Talk, NP, and Sitepoint. If you want to set a price, websites usually go for a few times the monthly profit.
ive seen a valuation rule of 10months adsense income if its an adsense based site. But then age/size/content/domain will be taken into account.
Anyhwhere from 10 month - 2 years revenue, This also depends on how old the site is , and if you can prove all income
Cost of website is determined by various factors, some of them are: 1. Revenue - Websites are normally sold at 8x-12x revenue per month. This could vary depending on the history of your income. 2. Age of the website - older the better. 3. Content - IF your website has a lot of unique content it would boost up the value of the website. 4. Design - A unique and good design gives you some extra money. 5. DMOZ/Yahoo - Listings in DMOZ or Yahoo or bcentral gives you an edge as well. 6. No. of backlinks for your website - the more the better 7. COOP or Vaultage generated through your website - This is dependent on the no. of pages indexed and your PR. 8. Page Rank - Google's PR gets the user to know the importance of your website, 9. SERPs for the keywords your website is targeting - if you are ranking high for a popular keyword it would add up to the value. 10. Traffic on your website. Not to mention that you have to prove everything you say in your sales pitch. Websites using turnkey scripts are not popular and they rarely sell. MySpace resource websites normally sell for 2x-4x the revenue as almost all of them are relatively new and have AdSense/YPNs 2-3 months history only. Same goes for arcade websites. Hope it helps.