Agree with melosu58... here's another place to check out:
I got all my live rock from them. I gave them a call, told them what I envisioned for my aquascaping, and they told me what they had in their tanks that they thought would do what I wanted. You can look at my tank in my gallery and see that I got some HUGE chunks of rock that would probably be considered "show" pieces... but they charge the same price no matter what the size of the piece.
I ended up going online because like you, my LFS
wanted big bucks for rock that wasn't that exciting. For me, the risk of taking rock sight unseen was worth it, but I wouldn't recommend doing it unless you can actually talk to the folks picking out the rock and have a general idea of the size of pieces you're getting.