I am seeing pages and pages of Open Road/Mysterious Press books going for $0.25 each in the US. And they are discountable at Kobo US, where "Partners22" is still working for 40% off, which makes them $0.13 each if you have both VIP and the code. (Remember that "Partners22" is multiple use, but one book per cart, so you have to do multiple carts/checkouts to use it on more than one book.) Not quite as good as the Open Road freebie-thon from several years ago, but pretty close.
There are way too many to list, but here are links which should show these books at both Kindle and Kobo US. But if you have a favorite Open Road/Mysterious Press author, you might also just check their books specifically.
Some authors I've noticed with at least one book at this price include (not an exhaustive list): William G. Tapply, Dorothy Hughes, Donald E. Westlake, Susan Dunlap, Ted Wood, J. Robert Janes, Dorothy Salisbury Davis, John Lutz, Barbara Parker...
Kindle US:
https://www.amazon.com/s?k=Open+Road...price-asc-rank
Kobo US:
https://www.kobo.com/us/en/search?qu...cmaxprice=0.59
NOTE: the links are a little finicky, probably because Open Road/Mysterious Press list themselves in a bunch of different ways, e.g. Open Road only, MysteriousPress.com/Open Road, Open Road/Mysterious Press, etc... If anyone can improve them, please do!