Surprisingly, it doesn't seem to have been mentioned in this thread yet, but the first 10 novels of British author Peter James' (
SYKM,
Wikipedia) Barry Award-winning Roy Grace series, starring the eponymous Sussex Detective Superintendent, from Pan Macmillan is on sale at Kobo Canada (not discounted in the US, where they appear to be $8 USD apiece) through the month of June, for just $3.99 CAD each.
They are all couponable (and the 50JUN 50% off unlimited coupon is still working, though probably only for the next couple of hours, even if they did restore the promo banner to the frontpage) and this is the promo page for it, if you think you might want to do some last-minute impulse shopping (10 titles in all):
Each title in Peter James' Roy Grace series is just $3.99 until June 30
(ETA: price-matched at Amazon CA but not Google or iTunes, from the looks of it, and only for the first 10 books, not the entire series.
#11 is $5.66 CAD.)