A whole batch of books in Kerry Greenwood's Phryne Fisher series have recently dropped to $2.99 at Kindle US, but sadly not at Kobo US, at least as of now, where they would be discountable. But, $2.99 is a pretty good price, and some of these don't go on sale very often, so if you're looking to plug some holes, take a look. A couple of early ones, but mostly later in the series.
Nine titles is too many for me to type out and do all the links, but here's a link to the series webpage:
https://www.amazon.com/dp/B086WFFPCM...kindle_edition
And then when I was checking Kindle UK for this, just for fun, I noticed that
Murder in Williamstown, which is the twenty-second and most recent book (2023), is on sale in the UK for £0.99, probably just for today.
Kindle UK:
https://www.amazon.co.uk/dp/B0BLLH11H8
Kobo UK:
https://www.kobo.com/gb/en/ebook/mur...williamstown-2