You can guess what price someone paid for a property by looking at its listing price. A Realtor in the area where you're interested normally has access to sold prices in MLS, but these cannot be published, such as on a website. Realtor MLS rules require that the person who receives the information be known by the Realtor before any disclosure of private MLS data can be made. Data from other public sources can be used.
Trula members should not be disclosing sold prices from MLS in Trulia without permission of the principals.
There are other sites that estimate the value of properties, such as Zillow, but frankly we don't know where they get their information from.
Your best bet is to ask a Realtor about a particular property.
Good questions. As the other have answered, home sales prices are not publically disclosed in Texas. However as agents, we often have access to this information. Normally we will provide to our clients when they are ready to purchase a home. Lot sizes are somewhat more difficult as they are also not listed. We again have some access to the information through the MLS system.
What are you trying to accomplish? There may be another method or source of the information you need.
Prudential Texas Properties
Colleyville, TX 76034