You can't compare a mass produced easily distributed item with a fixed asset produced at a slow rate like housing. It's easier to react to supply/demand changes with something massed produced and mobile.
So far as Sako's being twice the price in SA as what we pay here I can't comment on. It's a completely different country, economy, with laws & regulations that have recently undergone some huge changes. That and the fact that the market there is tiny by comparison.
Canada and the US on the other hand have very similar economies. There is a certain consistancy in price difference between products on both sides on the border for the most part. Double the cost of what is available across the border is considerably over that threshold in my opinion, hence posing the question.