Realty trac is a service that publishes a list of homes that are in the pre-foreclosure stage. The homes may or may not even be able for purchase. They charge a fee just to look at the list. However, none of the properties can be viewed until they are listed for sale, generally with a realtor. The 'price' may also be misleading, it's not an asking price for the home, but the cost of a lien on the home, so the balance of the mortgage, or the home owners association fees, or a second mortgage, some loan that has to be repaid when the home is finally sold.
If you are interested in purchasing a home, the smartest thing you can do for yourself is to find a good realtor to work with.