Nikon and Leica and I'm sure other camera companies hold their dealers to minimum prices they can sell some or all of their products. If they sell below these prices they can lose their status as an authorized dealer. In the case of Nikon it is their bodies and most lenses. It appears that batteries are not on the list. It may be that Nikon Canada also has batteries on the minimum sales price list. The only other thing I can think of is maybe Canada has higher duty on imported batteries.