Your odds of getting through the regular lines without additional charge are decent if you have 2x the limit or less and you declare it. You do need to be prepared to pay though. Also helps if you are not maxed out on your other limits.

The amounts due on overgages in AB is not ridibulous at all, it is the same tax that is levied on the product sold in the province. Other jurisdictions may vary due to collection of Provincial taxes (last I heard AB had not joined this group).