Whatever the reason for the higher prices, expect to pay usually 2-3 times the price for an airsoft gun in Canada compared to what you'd pay for that same gun from an American or Asian retailer. Sometimes you may luck out and get good deals on a new gun, but that's a general price line you can expect to pay.
And as mentioned, often you find used guns that have been upgraded with metal slides, better internals, or sell with extra magazines or a holter. Often these are prices about the same or only slightly higher than the comparable gun new. They may cost a little more, but usually quite worth it...