Ditto on what was said above. If you can't find rock locally that is closer to the price of the rock itself and the shipping from an online vendor, let your wallet be your guide. I believe in supporting my Local Fish Store, if they are a good one, but $8.99 for rock is way too much.
Beware of anyone trying to sell you "live sand" in pre-packed plastic bags. There
may be some bacteria in there, but personally, I think it's hooey. Similiarly, don't buy 100 lbs of live sand. If you don't know any reefers in your area who can give you a handful or two of live sand, you may want to look at buying 10 pounds, if it has "critters" in it. The stuff is expensive to ship though, because of the water weight.
You will get critters (worms, copepods, amphipods, mysis shrimp, mini-
brittle stars and the like) that will come in on your live rock, but buying a
detrivore kit, or getting some live sand full of critters, is a good way to boost the population.
HTH,
Alice