It would be nice if there was an option in Advanced section to completely ignore a specific country in the search results. I find myself clicking the 'free shipping' button in order to ignore the United States, but this also removes some sellers that I might find interesting or reasonable from other countries.
Like some of the other buyers on here, I choose to ignore dealing with anyone located in the US, due to extremely high shipping, high duties, and ridiculous taxes. It just isn't worth buying anything there, when I am shipping to Canada.
For example, I bought a Used $100 camera. When it arrived on my side of the border (shipped via USPS of course....) They were trying to charge me $125 in duties. Yeah... sorry I don't think so. So I brokered it myself and managed to knock it down to about $20 (which is still very expensive).
None the less, It would be nice to see an option to ignore a whole country. It would allow more accurate results to the buyers needs, faster, minimizing the amount of searching required.