Sales of tax deed are different from a tax lien, though both are available at auctions held by the government. Tax deed sale occur when the local government sells foreclosed properties rather than the money owed on them. In other words, you as the investor buy the immediate rights to the property.
In order to cover the tax debt of the previous property owner, the local government has the choice of selling the lien certificate or the deed of the property. Plus in a tax deed sale, the property owner has no choice but to surrender his rights to the property.
So, for a couple of grand you can buy a nice looking house in a good location through tax deed and lien sale opportunities. These are methods which makes it possible for you to get inexpensive homes.