I'm going to add one more thing. I don't mean any offense to anyone BUT most of the local dry rock I have seen doesn't have as nice of shape to it as the live rock I've seen. When I got that rock from Premium Aquatics (and previously when I bought good live rock from Aquatic Specialists), it's full of holes and caves and sometimes has coral polyps, sponges, or nice macro algaes on it. PLUS almost everyone that I've seen use that dry rock later has a problem with algae. I don't know if there's some extra phosphates in it or what...but for whatever reason that dry rock tends to promote algae growth, in my experience.
I just don't think it's as quality of a buy. PLUS it takes a long while to look like reef rocks because they're so sterling white.
Very true!