The Local Expert badge is awarded to those who have made valuable contributions in a specific city or neighborhood on Zillow. Local Experts are active Zillow users who share their real estate knowledge and help others by contributing high-quality content at a local level. The more and better the contributions a user makes that relate to that city or neighborhood, the more likely an award will be granted. Users' contributions can be seen in their profiles.
The best way is to call a realtor from you area and ask for a CMA...Comparative Market Analysis. This method will take recent, similar homes that have sold in your area, average them and give you a "market value" for your home.