Both replies to your thread Vegannah are right on. You can save yourself money by starting off with dry rock or even base rock encountered at various pet shops. Also, if you know someone breaking down a tank or that is willing to give you or sell some rock cheaper than at your local pet shop or online, that is another viable alternative.
Having said this, however, you may want to purchase a few pounds of live rock, either cured or uncured, depending on your circumstances, because this rock contains many unique and diverse life forms from bacteria to microcrustaceans and polychaete worms endemic from where the rock is found. This adds to your flora and fauna in your tank!