A couple of titles in Kerry Greenwood’s Phryne Fisher series have dropped to $1.99 each at Kindle and Kobo US, discountable at Kobo. These were on sale not too long ago at $2.99 each, but if you didn’t bite then, now you have a chance at a better price :). Note there are a couple of editions, so check carefully before you buy.
Buy:
Murder in Montparnasse, #12: Kindle US | Kobo US
Unnatural Habits, #19: Kindle US | Kobo US