The purpose of the GST is to make the US seller more comfortable with shipping internationally.
It has few benefits for the buyer, unless the item is very heavy or is valued over $100.
The SELLER is protected because she only has to prove delivery to the GSP plant in Kentucky. After that, delivery is the responsiblity of the GSP.
The SELLER is also protected because the buyer cannot leave negative feedback about Canadian duty or taxes, or about slow delivery.
If I buy item in USA and ship to CANADA do I have to pay custom CANADIAN taxes
YES.
Any item valued over $20CDN (about $14USD at the moment) may be assessed for duty.
There will be Sales Tax on those items.
There will be a service charge from the carrier for wrangling the purchase through customs.
The Global Shipping Program covers Canadian duty, Canadian sales taxes, and a ~$5USD service charge. This is what your $130 is made up of. There is usually also a 'shipping charge' that covers shipping the purchase to Kentucky with tracking.
There will be no further Canadian charges on your purchase.
For duty on your item look here:
http://www.cbsa-asfc.gc.ca/travel-voyage/dte-acl/est-cal-eng.html
Remember that the sales taxes (PST/GST/HST) will vary depending on your province.
