Is ther anything better than Zillow?

[Dan Krause]

For doing comparisons of commercial and multi-family propertioes for sale? Dan

[Joshua Dorkin]

If you're looking for other websites, here's a list:
Find House Values & Comps

Otherwise, the honest answer is that any appraiser will give you better values. Most realtors can do so as well, and if you get to know your farm, you can likely determine a better value just by getting the details on a property.