There is base rock which is just dead rock that is dry with nothing on it. There is live rock too. I have no experience with the uncured live rock which is rock that is "live," but has yet to see a cycle. I bought cured live rock which I find that the average price is about $8 a pound, but can go as high as $15 a pound. It really depends on where you are located in combination with the supply/demand for the rock in that area.