You may have seen some of the new websites like Zillow.com for sales and now Zilpy.com for rentals.
I entered in one of my listings just to see how accurate the data was. It was suppose to provide me with some detail on pricing in the area. WOW, was it off by about $2,000!! I've used Zillow also to search sales and again the data is simply off. You cannot really use this information to justify pricing. Yea, it looks cool, well organized but if the information is simply no good why use it.
Hint, want to know what something should really rent for you. Contact me and I'll show you. We have the real data and the real computer systems that have accurate data.