Sunny27-I know that auctions fall under these categories when the auction is a judicial auction that is done on the courthouse steps.
These cash home sales are done quickly and the bidder has to provide the remainder of the winning bid by the end of the day.
Most of these bidders are seasoned investors that have access to funds by either cashing out the equity in another property or money that they have saved up through their real estate investing.
This type of cash sale is not recommended for a beginner because most of these homes have substantial liens that the winning bidder would be required to pay in order to get a clear title.
Bank sponsored auctions like those done by REDC are better because the bank owns the property free and clear and they have cleared any liens on the property. With this type of sale you do not have to worry that you will be responible for any liens.