Zillow vs Redfin House Pricing Data

[Vera Shokina]

What do you find as the best data source for house prices?  I notice significant difference (up to 20%) for the same property on Zillow, Redfin and Homes.com.  Zillow consistently shows prices much higher than Redfin, for example.  Which site is the most accurate to estimate the fair value of the house based on your experience? 

[Rick Albert]

Neither, you need to dig into each sale yourself. The problem is these are automated values that don't factor things in like views, condition, or even if one block of homes sells for more or less than another.