One of the challenges in setting a listing price is that owners are sometimes convinced that they know the value of their homes because Zillow told them so. And it may be right, or it may not. Real estate websites use a program called an Automated Valuation Model (AVM) to determine the value of your home. However, each uses different mathematical models and data bases to come up with the value of your home. As a result, there can be quite a range, depending on how you ask. To test it, I looked at the AVM for one of our former listings in Cornville. I checked five different sources, including Zillow, Trulia, Realtor.com, Homes.com and RPR. The low estimate was $287,842 and the high estimate was $311,800, with the others somewhere in between. That's a swing of nearly $24,000. Depending on which estimate you use, you may be very happy or very unhappy. The best way to get an accurate, and relevant estimate is to talk to Jan and Wally.