Fourteen (Kobo) or fifteen (Kindle) titles in the Aimée Leduc series by Cara Black are $1.99 at Kindle and Kobo US. Too many to list - just use the links below...
Kindle US:
https://www.amazon.com/gp/search/?se...price-asc-rank
Kobo US: https://www.kobo.com/us/en/search?Query="cara+black"&fcSearchField=Author&fcm axprice=1.99&fcminprice=1.99
In addition
The Aimee Leduc Companion: A Guide to Cara Black's Paris, is free right now if that sort of thing interests you.
Kindle US:
https://www.amazon.com/Aimee-Leduc-C...dp/B004Q3RMR6/
Kobo US:
https://www.kobo.com/us/en/search?Qu...educ+Companion