Confusing information in cart: import charges and shipping costs from US to Canada

[123.chemist]

I have called eBay twice and I got 2 different answers....unfortunately no one is able to clarify this situation. 

In the attached photo of the cart there are discrepancies between the costs listed on the right side and the total costs listed on the top right side. 
More specifically, the Delivery paragraph on the left side details the fact that the import charges are not included, and the amount is  an exorbitant 815$ for shipping ( via Global Shipping Program) a 4000$ item. 
Also this side of the cart mentions import charges of 739$. 

In contradiction to all this, the top right of the cart lists the price of the item, the shipping cost of 76$( corresponding with the shipping calculator amounts in the listing) and the import charges of 739$. 
It is very confusing to see  a significant discrepancy of 815$ in the same cart. 

Being located in Ontario/ Canada and attempting to purchase a piece of fine jewelry from US, I am obligated to pay only the Ontario taxes. According to the CBSA there is no duty for  purchases for fine jewelry for personal use from USA, for an item made in USA, as in this situation of the item I added in the cart. 
Doing the math it seems that the import charges listed in the cart amount to 17% of the item cost, which is also a discrepancy because the Ontario tax is only 13%. I suppose that there are brokerage fees as well. 

In conclusion I do not understand what is with the amount of 815$ for shipping. This Global Shipping Program has excessive costs ? Or it is added in the listing for shipping overseas maybe. In any case, it is confusing and is deterrent to Canadians who are attempting to purchase from USA. 

I wish eBay would correct its algorithms to ensure that the proper information is showing up in the cart and also that the information is accurate. 

[marnotom!]

Continued here: https://community.ebay.ca/t5/Buyer-Central/Confusing-information-in-cart-regarding-import-charges-an...