The seller has the right to choose the shipping service she believes will be secure and timely and also protects her interests with insurance and confirmation of delivery.
The buyer can ask, before bidding, if the seller is willing to ship by USPS First Class International Parcel, which does offer Delivery Confirmation to Canada and handles up to four pounds of product. She can agree or not. If she doesn't agree, move on.
You should be aware that the amount PB charges is made up of Canadian duty, Canadian and provincial sales taxes and a service charge covering the cost of getting the parcel from the USA to your doorstep. That charge seems to be in the $5 range.
Given the amount you claim to have been charged it is likely that you bought a fairly expensive item. Those are the ones that CBSA is more likely to stop and assess. If that were the case, instead of being presented with a $55 import charge before the seller will ship, you would be given a choice of paying the same duty the same tax and a $10 Canada Post service charge before the parcel is handed over. If you don't pay up, the parcel will be returned to your seller and you will have to go through the hassle of getting a refund for a refused item.
