You do not. Sorry, realtytrack listings are bogus. You can not buy them for the price listed.
Often they show the amount of a lien that is behind on payments. The house may never be an actual foreclosure. If it is, the price shown will look nothing like the price paid for it.
To find foreclosures either look at the blog below and search for real ones or contact any realtor. They can show you all real foreclosures for sale.