Indeed, zillow is really not that accurate since it does not take into consideration the condition of your house. If you have done major remodeling, inside and outside, then the value of your home will tend to go upward and vice versa. Zillow bases its estimates on the home that have sold and is also probably computer generated.
Now the aim of the real estate game is to price your property just right in order to find a ready, willing and able buyer in a very short period of time. Having a real estate professional come to your house, someone that knows the market and your neighborhood well, will help you win that game.
In order to get a more reliable figure have a real estate professional run the comparable of the houses that just sold in your neighborhood. Have the agent create a complete Competitive market analysis, called CMA, with detailed photos, sources...
When selling a home 1-4 units, the principle of substitution exists: It means that if a buyer can purchase a house 2005, 4 bedroom 3 bathroom, 2200 square foot house for $480,000 in Lemon Grove, why would someone pay $570,000 for a similar 2005, 4 bedroom 3 bathroom house?
Let me know if I can be of any use,
Allied Green Realty