Well, Kobo does have coupons applicable to non-Agency books (which in Canada, means all the US-Agency books except for Hachette/Little Brown/Grand Central and a few others).
I don't know if the prices would still be too high after you've managed to knock them down by 20-30% (usual Kobo coupon amounts) or more.
But for me I find them much cheaper for the kind of books I buy than Amazon (also, faulty ePubs are easier to fix than faulty Mobi). ~ $3.50-5 CAD including taxes, versus $6.29 charged in USD wins out every time. Even with the change in the relative exchange values of both dollars.
But yeah, their search engine really needs an overhaul. Technically, another overhaul, since they "improved" it from the barely usable unhelpfulness it used to be.