A Drop of the Hard Stuff is the seventeenth in the Matthew Scudder series by Lawrence Block. It has dropped to $1.99 at Kindle and Kobo US. Block is probably better known for his Bernie Rhodenbarr/Burglars series, but I’ve read and liked many titles in the Scudder series as well.
A Drop of the Hard Stuff is $1.99 in the US again today. The links in the OP are still good.
All the Flowers Are Dying is the sixteenth Matthew Scudder book. It’s $1.99 right now in the US.
Kindle US: https://www.amazon.com/dp/B000FCJZ0Y
Kobo US (discountable): https://www.kobo.com/us/en/ebook/all-the-flowers-are-dying-4
All the Flowers Are Dying has now dropped to $0.99 at Kindle US, but not at Kobo US, and not in the UK. The link in the comment just above is still good, and you can easily price-check at Kobo US too…
Four books in Lawrence Block’s Matthew Scudder series are $1.99 each in the US right now, and the first one is semi-long-term at £1.99 at Kindle UK.
The Sins Of The Fathers, #1
Kindle UK: https://www.amazon.co.uk/dp/B005XBUENY
Out on the Cutting Edge, #7
Kindle US: https://www.amazon.com/dp/B000FC137C
Kobo US: https://www.kobo.com/us/en/ebook/out-on-the-cutting-edge-1
A Dance at the Slaughterhouse, #9
Kindle US: https://www.amazon.com/dp/B000FC11BK
Kobo US: https://www.kobo.com/us/en/ebook/a-dance-at-the-slaughterhouse-1
The Devil Knows You’re Dead, #11
Kindle US: https://www.amazon.com/dp/B000FC11EC
Kobo US: https://www.kobo.com/us/en/ebook/the-devil-knows-you-re-dead-1
Hope to Die, #15
Kindle US: https://www.amazon.com/dp/B000FC126O
Kobo US: https://www.kobo.com/us/en/ebook/hope-to-die-1
Even the Wicked is the thirteenth in the Matthew Scudder series by Lawrence Block. It’s $0.99 right now in the US.
Kindle US: https://www.amazon.com/dp/B000FC11LU
Kobo US: https://www.kobo.com/us/en/ebook/even-the-wicked-a-matthew-scudder-novel
Eight Million Ways to Die is the fifth Matthew Scudder book. It’s $1.99 in the US right now.
Kindle US: https://www.amazon.com/dp/B000FC11K6
Kobo US: https://www.kobo.com/us/en/ebook/eight-million-ways-to-die-1
A Ticket to the Boneyard is the eighth Matthew Scudder title. It’s $1.99 right now in the US.
Kindle US: https://www.amazon.com/dp/B000FC147Q
Kobo US: https://www.kobo.com/us/en/ebook/a-ticket-to-the-boneyard-1
Two more Matthew Scudder price drops, to $1.99 each in the US.
When the Sacred Ginmill Closes, #6
Kindle US: https://www.amazon.com/dp/B000FC14HQ
Kobo US: https://www.kobo.com/us/en/ebook/when-the-sacred-ginmill-closes-1
Everybody Dies, #14
Kindle US: https://www.amazon.com/dp/B000FC11MO
Kobo US: https://www.kobo.com/us/en/ebook/everybody-dies-1
In the Midst of Death is the third Matthew Scudder book. It’s $1.99 right now in the US.
Kindle US: https://www.amazon.com/dp/B000FC12B4
Kobo US: https://www.kobo.com/us/en/ebook/in-the-midst-of-death-1