Are the items you are offering on available to Canada?
Many US sellers will not sell outside their own country.
If you really want it, you can Contact the seller and ask if he will open the listing to you or to Canada. From a tactical point of view, combining this with an offer less than the asking price is unlikely to succeed.
Are you bottom-feeding?
Many sellers have an automatic block on offers below a certain price.
You may be able to buy something for 10% less, but less likely to succeed with an offer of 20% less.
And if you are offering only 10% of the asking price, you are just being insulting.
(Numbers are not meant to be any reflection on your practices. But you would be amazed...)
