There's typically a $10 per bottle difference between BC and AB whisky prices and it's all due to the different rates of "sin taxes" applied by the provinces. In Canada taxes on items such as alcohol, tobacco, fuel, etc. are applied at both the federal and provincial level which can lead to radical differences between provinces (petrol is about $0.30/L cheaper in AB that it is in BC
To augment Mithril's comments - the pricing differences can be much greater than $10/bottle... as there are several differences impacting the BC/Alberta divide (beyond the Rocky Mountians).
Alberta applies a flat tax versus B.C.'s % tax... so $10 per bottle may be the norm at the low end of the price spectrum - the gap widens substantially as the price point increases.
Alberta privatized their liquor stores - allowing for capitalistic competition - and market responsiveness to work its way into the equation. BCLDB - try as the might (in their own minds) don't know up from down and never cease to amaze me with backward thinking, supply inadequacy and painful pricing...
Other fine examples:
Springbank 10 - BCLDB = $95.07 Cdn
Springbank 10 - Alberta = ~$55 Cdn
Bruichladdich Blacker Still - BCLDB = $260 Cdn
Bruichladdich Blacker Still - Alberta = $170 Cdn