there are plenty of people selling live rock for $1to2 a pound wich is much better than having to wait for dry reef rock to get established and you will be saving a lot of money for whatever you want to put in your tank.
Dry rock is a good way to go. You won't be paying for water weight, and no danger of pests getting into the tank from the get go. I'm a fan of pukani Rock, bulk reef supply sells it.