Hello 'engineerdoug...',
<<Why do I pay I'mport charges when buying from the U,S, and they don't have import charges ??????>>
All importers must pay charges when buying from outside their own country, and when you buy from outside Canada you are the importer. How much a buyer pays depends on which country he lives in, what the item is, and where it is made.
In Canada any item with a declared value over $20 Cdn (about $15 US at the moment) may be subject to duty and taxes. This is imposed by our government. Have a look at the following link:
http://www.cbsa-asfc.gc.ca/import/postal-postale/duty-droits-eng.html
If you wish to minimize the chances of paying charges, first try to find your item from a seller in Canada.
Type your terms into the Search bar, and click to 'go'.
Then, -- because it is always a two step process, -- pick Price + Shipping: Lowest from the Sort bar,
and over on the left under Item Location, choose Canada Only.
Make sure you have the View set for List and not Gallery.
If you still cannot find what you seek, again from the Item Location try North America, and when you scroll through the offerings be sure to avoid those listings which say in pale grey,
Customs services and international tracking provided
That is a Global Shipping item, and all GSP items will have the charges added on. So pass those by, and find a seller who ships USPS First Class.
And of course, do not by anything that is shipped by a courier. Couriers, like the GSP, are required by law to collect any charges, whereas items coming through the post are often not assessed if they are lower value items.
If you do have to pay charges from time to time, do so graciously and without argument. It is the cost of being Canadian, and is never the fault of the person delivering your parcel.
Happy shopping 
