The Sanctuary Murders is the 24th and most recent (2019) in the Matthew Bartholomew series by Susanna Gregory. It has dropped to $0.99 at Kindle and Kobo US. I like historical mysteries a lot, so I’m a bit biased, but I’ve enjoyed several of the earlier titles in this series.
The first two books in this series seem to be permanently at $0.99 and $1.99 respectively, so you can try the series on the cheap if you want to.
A Plague On Both Your Houses, #1
Kindle US: https://www.amazon.com/gp/product/B00GW4QD72
Kobo US: https://www.kobo.com/us/en/ebook/a-plague-on-both-your-houses-1
An Unholy Alliance, #2
Kindle US: https://www.amazon.com/gp/product/B00GW4QD7M
Kobo US: https://www.kobo.com/us/en/ebook/an-unholy-alliance-4
And the eleventh book, The Mark Of A Murderer, has been at $1.66 for several months…
Kindle US: https://www.amazon.com/gp/product/B00GW4Q8IQ
Kobo US: https://www.kobo.com/us/en/ebook/the-mark-of-a-murderer-1
The Killer Of Pilgrims is the sixteenth book in the series. It’s $0.99 at Kindle and Kobo US right now.
Kindle US: https://www.amazon.com/dp/B00GW4QE8K
Kobo US: https://www.kobo.com/us/en/ebook/the-killer-of-pilgrims-1
The Chancellor’s Secret is the 25th, and most recent, and supposedly final, book in Gregory’s Matthew Bartholomew series. And it’s $0.99 in the US right now, while not having dropped in the UK. This is quite odd – usually most-recent-in-series books drop very briefly to £0.99 in the UK shortly after publication, months before they drop in price in the US. But I’m not complaining…
Kindle US: https://www.amazon.com/dp/B08HHXBJ21
Kobo US: https://www.kobo.com/us/en/ebook/the-chancellor-s-secret-1
ADD: This is part of Kindle’s Pre-Black Friday limited time deal, supposedly good through 11/21/21. Still, I wouldn’t wait until the last minute if you want it…
A Wicked Deed is the fifth in Susanna Gregory’s Matthew Bartholomew series. It has dropped to $2.99 at Kindle and Kobo US.
Kindle US: https://www.amazon.com/dp/B00GW4Q8G8
Kobo US: https://www.kobo.com/us/en/ebook/a-wicked-deed-1
The Chancellor’s Secret has dropped to £0.99 at Kindle UK right now: https://www.amazon.co.uk/dp/B08GPKRHF2
The Habit of Murder is the 23rd in the series. It has dropped to £2.99 at Kindle UK: https://www.amazon.co.uk/dp/B01N4R2YUM
And The Chancellor’s Secret is still £0.99 in the UK – see the link in the comment just above.
Murder By The Book is the eighteenth in the Matthew Bartholomew series by Susanna Gregory. It’s on sale right now in the US ($1.99) and UK (£2.99).
Kindle US: https://www.amazon.com/dp/B00GW4JQQ2
Kobo US: https://www.kobo.com/us/en/ebook/murder-by-the-book-8
Kindle UK: https://www.amazon.co.uk/dp/B007TNY6II
If you missed it on sale before, The Sanctuary Murders is on sale again in the US, although this time it’s $1.99 and not $0.99. But that’s still not a bad price. Oh yeah, and the links in the OP are still good.
A Deadly Brew is the fourth in the Matthew Bartholomew series. It’s on sale right now for £2.99 at Kindle UK. That’s not a great price for decades-old backlist, but is better than eReaderIQ has ever recorded it – either in the US or UK. YMMV…
Kindle UK: https://www.amazon.co.uk/dp/B004BDOJOU
A Plague On Both Your Houses is £0.99 right now at Kindle UK: https://www.amazon.co.uk/dp/B004EHZPQY
A Deadly Brew is now $0.99 at Kindle US: https://www.amazon.com/dp/B00GW4Q886
Also the first and second books in the series (A Plague On Both Your Houses and An Unholy Alliance) are semi-long term at $1.99 if you want to try in order, and the eleventh book, The Mark Of A Murderer, is only $1.66. And four other titles in the series are $2.99 right now. Here’s a link to the series webpage for all of these: https://www.amazon.com/dp/B0CY2RZB7D?binding=kindle_edition
The Chancellor’s Secret is £0.99 at Kindle UK again right now: https://www.amazon.co.uk/dp/B08GPKRHF2