I just found an insane deal at my LFS, this is a multi lot of 18-20 large colonies on a put together coral. I saved around %75 buying it this way. I also am fragging colonies off of this one.
I'd personally rather grow my own colonies. My LFS usually has decent sized colonies for $39-100 depending on what it is, sometimes more. Try craigslist for an old fellow taking down a tank. Usually I can find those, too.