Hmm I am not sure what you can buy here thats not already sold in US for a lot less (well import Belgian beers are now cheaper here in some cases)
I am not sure which province you are visiting but if you can find I would recommend 30 year old Alberta Premium. Just amazing for what you pay.
There are all kinds of Canadian Whiskies that are not exported to the US or not exported in any significant quantity.
I haven't tried many of those since they don't make it down here, but some I would try if I were up there:
Canadian Rockies 21