Lisa, if you are looking on Realty Trac this could be a teaser ad - properties 'sell' at the courthouse steps for $100 because the bank is buying the house back for a nominal fee. Later the property will come on the market unless it is sold to an investor first who has a relationship with the bank asset managers. So, yes they sell for $100 when the bank buys it back but more when it comes on the market.
Believe it or not sometimes properties are sold for $1, but you have to realize that those properties were probably very run down and even the government agencies didn't want them. So what do you think you're going to get for that price?