And some more £0.99/£1.99 first/second in series recent price drops at Kindle UK...
Publishers seem to be Constable, C&R Crime, and Sphere, so I went looking by pub rather than by authors on my eReaderIQ list.
John Corey series by Nelson DeMille:
Sam Capra series by Jeff Abbott:
Ash Rashid series by Chris Culver:
Col Vaughn de Vries series by Paul Mendelso:
Hilary Tamar series by Sarah Caudwell - probably my most favorite mystery series, although depending on my mood, Catherine Aird/CD Sloan or either of Michael Pearce's series also occasionally get the nod