For years, it's always been that if the value of your parcel exceeds CA$60 after current exchange rates, and so forth, there is a duty charged according to type of item plus the appropriate taxes according to your province both federal and provincial. Of course, if they have to collect upon delivery, there is also a customs/postal service charge of what used to be $5 for their trouble.
Now this is for packages marked as "gift" where they also have no reason to suspect it's a purchase.
In the past, as I was shipping to the UK, I had purposefully marked a lower value also since it seems the "gift" value allowed there was about the same though I can't recall if it was US$60 or CA$60 but the magic number seemed to have been $60 also.
It's become such a habit of mine to always say $20 to $40 for anything when I'm shipping out so long as it's not something requiring insurance, etc. I don't believe the magic number has changed over the years.