We get our salt from Ontario Salt @ $2.85/bag for 20kg delivered. That price is good for 4 or more skids (56 to a skid).
I called Innovative Municipal in Ajax, and they referred me to SuperChem in Weston. I don't even know where Weston is exactly, but they gave a price of $5.90/bag (not including delivery). He's getting back to me on a shipping fee, but that's a pretty high price to pay. More than double that of rock salt. We're willing to try some out, but it'd better be pretty amazing stuff to justify the cost.
Which Canadian Tire in Mississauga has it? Maybe we'll drive out and just buy a few bags to see how it works?