I buy mine at the Purple Foot in Burnaby. They kind of look at you weird when you say you want to buy some, but I think I got mine for $1.50/ea. They didn't really know what to ask for since they don't have many people who actually buy them.

I use the dromedary bags. I have 2-10L and 1-6L and yes they often make the water taste bad. We pump our fresh water straight from a lake untreated so bromine has nothing to do with it.

Reliance fold-a-carrier bags, from Canadian Tire, work well.