Realty Trac collects public data from courthouses about legal proceedings on real properties. The fact that there is a legal proceeding on a property is not indicative that it is for sale. Many homes that are the subject of legal proceedings are resolved through other means. Quite commonly, these legal actions are foreclosure complaints. Resolution may come in the form of restructuring the financing, leveraging other assets, borrowing from friends or family, or a formal repayment plan through a bankruptcy.
Because you see a property listed on Trulia, it mistakenly leads one to believe it is for sale. It may not.
You can pay Realty Trac for additional data....or you can work w/ a Realtor who can provide the same data to you for free if you are their customer or client. A Realtor can contact the homeowner and inquire if a property might be for sale. Quite often, the homeowner does not know what they intend to do, and may not be receptive to your inquiry. Other times, properties listed on Realty Trac are already actively listed on MLS. A Realtor can help you either way.
The amount listed on Realty Trac represents the amount involved in the legal action, not the "for sale" amount. There might also be other liens against the property and in order to pass clear title, all liens need to be cleared.
You might also want to look into REO properties.