If you've been in real estate for awhile, I'm sure you've heard of www.zillow.com
I critically analyzed this site again for several hours and am happy to report that www.Zillow.com
is getting much better in predicting real estate comps.
Early this year, I checked this site and it was apparent that their algorithms were not accurate in Pima county (Tucson). The root cause for their errors may have been coming from the projection of values based on super high appreciation rates. Last year, Tucson appreciated over 20%.
The values have come down approximately 40% in the last 6 months and am very surprised that values are spot on for all of my properties. Of course real estate did not come down 40% , but its probably zillow's best way to correct the graphs. For some properties, I needed to update the proper square footage because the values in the assessor's records are not accurate.
This site is good because you can find comps that sold only a month ago. Thats fabulous, last year, I paid www.dataquick.com
several dollars for one search for the same service.