The prices you see on Trulia (and other websites, such as Zillow) are controlled by the internet company., often derived from a formula for a large surrounding area. Their formulas unfortunately severely understate Darien home values.
Similarly, the tax assessment they show comes from public records and should be correct. BUT - Trulia doesn't tell people that the tax assessment amounts are 70% of the Town's appraised value. So in the case of 16 Dubois, the 100% Town appraisal is actually $803,900, not the $562,730 as stated without any qualification. Even worse, the Trulia "estimate" of the property's value is only $232,014, largely driven by homes in Stamford and Norwalk.
As you can imagine, the gross inaccuracies of these internet real estate "estimated values" are a great source of frustration to home sellers and real estate agents. Hope that eases your mind a bit.
WILLIAM PITT SOTHEBY'S INTERNATIONAL REALTY
1057 POST RD. DARIEN, CT 06820
Servicing buyers, sellers, renters, andlandlords in Fairfield County, CT