Two books in Steven F Havill's excellent IMO police-procedural Posadas County series are on sale right now for $1.99 each in the US, and also on sale in the UK.
Red, Green, or Murder, #10
Kindle US:
https://www.amazon.com/dp/B07VLBR2M4
Kobo US (discountable):
https://www.kobo.com/us/en/ebook/red-green-or-murder-5
Kindle UK, £1.99:
https://www.amazon.co.uk/dp/B07VLBR2M4
Scavengers, #11
Kindle US:
https://www.amazon.com/dp/B07VNH28F7
Kobo US (discountable):
https://www.kobo.com/us/en/ebook/scavengers-28
Kindle UK, £1.59:
https://www.amazon.co.uk/dp/B07VNH28F7
In addition, several titles in the series are $2.99 in the US - too many for me to list, but here are series page links if you want to check for yourself:
Kindle US:
https://www.amazon.com/dp/B084ZG1C62...kindle_edition
Kobo US:
https://www.kobo.com/us/en/series/po...ty-mysteries-2