While Zillow may be a place to start when determining a home’s value (called a Zestimate) it is not a good place to end!  Consider their own most recent statistics from June 15, 2011 for the San Francisco Bay Area: * Their median error on all Bay Area home appraisals is 7.2%.  That’s almost $40,000 off on a $500,000 home * Two-thirds of their home appraisals in the Bay Area are off by more than 10% * One-fifth of all “Zestimates” are off by a whopping 20% By simply averaging …