I've seen the same thing happen at Amazon. Dear Author (a book review website) will sometimes list books that are for sale (with links to Amazon/B&N/Sony/Kobo) and often the price at Amazon is higher for me, visiting the book link from Canada, than what the sale price is supposed to be. And then, of course, there are the lovely "not available in your country" messages on some of these sale books. Grr.
Prices are always higher in Canada, despite what our dollar is worth, and often it's the publisher who sets the book price for books sold here.