I'm a fan of marco base rock, and not to mention the customer service is great, and free shipping, I've heard people say that it raised their phos levels but I drop it in the tank at star up so I'm not too worried about that.
Supposedly reefrocks.net gets their stuff from the exact same mine. I payed $100 for 50 lbs of rock and 40 lbs of sand shipped. My last order was fine. Just issues with this one.