I did get a good discount, but I bought quite a lot. It was from Bali - they also had some Marshall Island rock in plates for about $12 - lots of worms on it. Plus some aiptaisia!! (vinegar and lime juice injection worked)
I know in the US a lot of LFS will charge $10 or $12 US. At J&L you can get it for as low as $4.59 CN - which is about as cheap as anywhere in N. America, I think. Or, even as low as $3.79 CN if you buy a lot.
http://www.jlaquatics.com/static/livestock/liverock.htm