Three more John, the Lord Chamberlain books, by Mary Reed and Eric Mayer, are $1.99 right now in the US, and discountable at Kobo US...
Four For A Boy, #4
Kindle US:
https://www.amazon.com/gp/product/B07VQMX3KJ
Kobo US:
https://www.kobo.com/us/en/ebook/four-for-a-boy-11
Murder in Megara, #11
Kindle US:
https://www.amazon.com/dp/B07VMH4RFM
Kobo US:
https://www.kobo.com/us/en/ebook/murder-in-megara-4
An Empire for Ravens, #12, most recent in the series, which seems to be dormant (2018)
Kindle US:
https://www.amazon.com/dp/B07VLBR8VD
Kobo US:
https://www.kobo.com/us/en/ebook/an-empire-for-ravens-1
And a couple of other books in the series,
One for Sorrow and
Ten for Dying, which were on sale a few weeks ago, are also on sale again right now. Info and links are in
this previous post. So you can actually get almost half the series on sale right now if you want to!