I misread your post as saying you'd found BJB at $2.99, not just some random USD books. It's 9.99 CAD in Canada, though, and our dollar is currently above par, last I heard.
But doesn't Kobo price in local currency? Though sometimes sellers set much higher rates for other countries than the US.
Open Road's Barbara Hambly backlist have a suggested list of $9.99 USD in the US, and...
$19.99 elsewhere, apparently. And Tor/Macmillan consistently inflate their $2.99 USD special sale offerings to $3.99 CAD in the Kobo store (those Tor.com stories they took the freebie downloadable versions off the site to monetize are 99 cents in the US and $1.99 in Canada). Guess which publisher I'm not spending my hard-earned fluctuating petro-dollars upon, even if they hadn't gone Agency up here as well.