Once you buy and sell a few homes you realize that having information about the home you are considering, other similar homes, the local economy and so on is very important to making an intelligent decision. Numbers, metrics and objective analysis drive the business. Without this information you are subject to the whims of the real estate agent and whatever their agenda may be. Whoever has access to the best data wins. Getting data in residential real estate is daunting. Most turn to Zillow, Trulia and Realtor.com. These sites either don't publish useful info or it is notoriously outdated or misleading info.
The answer is to hire a sharp realtor who does the research for you for market data only available to realtors through the MLS. A real estate professional is constantly running spread sheet analysis of recent solds, price per sqft, active inventory, days on market, etc. A good realtor knows this history of a home - if it sold for a low price, why did that happen - weak home, distressed sale, owner had family emergency, etc. Far too often folks shopping for real estate have low expectations of realtors. realtors have not been helpful in the past to them. Real estate is an area where an outstanding realtor can make the difference in helping you find a great home meeting all of the family's needs and making an intelligent financial decision. It only makes sense to interview your real estate agent just like you do your trusted financial adviser.