^
Here's an easy link to all the Simon & Schuster UK-published books which are price-matched in the Amazon sale, available @
Kobo for $1.99 each in Canada and presumably also the US.
(ETA: and Scribner for Ursula Blanchard and others @
Kobo; you'll have to scroll past a bunch of 99 cent essay shorts, but once you hit the $1.99 range, there's about a dozen sale titles across multiple genres)
In addition to sale titles by Michael Jecks & Bernard Knight, if you like those two authors you should also pick up their two "The Medieval Murderers" collaborative novels listed which feature them and a bunch of other medieval mystery-writing authors making a shared story involving their particular sleuths sequentially investigating mysteries centred around murder-attracting objects which get passed around down the ages.
They've also got some promising-looking non-fiction from Catharine Arnold on crime and death in London, which mystery readers may also may be interested in.
(ETA 2: I broke down and bought both of Arnold's books from Kobo. She's an academic and the samples showed pictures and footnotes, so I couldn't resist. Also, the other available book in her series of London history is regularly priced at $19.99, so they were probably close to literally 90% off.)
As for Amazon, I've personally read and enjoyed all three (thus far) of Leena Lehtolainen's Finnish-translated Maria Kallio mystery series which are exclusively available from the AmazonCrossing imprint, so I second the recommendation for them if you want to try a low-key Nordic police procedural (they're a bit retro since the original publication was in the early 90s, and very realism-oriented, so YMMV and here's
what I thought of the 1st in the Reading Recs forum if you want more details on that).