I have found that for smaller, inexpensive items, buyers won't pay the $17-$20 charge for Tracked Packet.
I did some thinking, and this is how I now sell on ebay, which is based on my comfort level ($20 being my threshold).
For items that are small, inexpensive, under $20, I ship those via Small Packet. For around $8-$10 USD. What I do is tack on an extra $2 for insurance, which I keep for myself in case a package ever runs into trouble. Which means I would have to refund out of pocket. This is why I only do this for cheaper items, $20 is the most I am willing to risk.
For items that are heavier (500-1000 grams) then the shipping via Small Packet is almost the same as Tracked Packet anyway. So if something is close to $20 or I get more for it than I hoped, then I charge the buyer $20 (postage plus $2) and chip in the extra myself for Tracked. This is on a case by case basis depending on how I feel about the buyer. (Small packet runs around $19, Tracked is around $22 for packages in this weight category).
For items that are more valuable, then tracking is mandatory. Some people will contact you asking if you will ship with a cheaper method, I just politely explain that the item is too expensive to ship without insurance, and it is being sent internationally from Canada, which means tracking and insurance are expensive. Most understand fine.
BE AWARE! Tracking and insurance are not available to all countries, and when it is it is VERY expensive. So I don't ship anywhere except USA and Canada.
Also note - Canada Post does not offer insurance for packages containing items that are 'inherently fragile'. Like things make of glass or porcelain. They will insure against them getting lost, but not against breakage. So if you do sell fragile things, package them up with extra care, DO NOT let the post office stick this 'fragile item' stickers on the box (that is like putting a "Kick Me" label on them!), and then don't declare them in a way that makes it obvious they are breakable. So instead of "Porcelain Figure" I put "Collectible Figure".