A couple of Dashiell Hammett Continental Op short story collections are on sale. Not sure how great a deal these are since they are around a hundred pages with three or four stories each. But they are on sale for $1.99 a piece:
Arson Plus and Other Stories: Collected Case Files of the Continental Op: The Early Years, Volume 1
The Main Death and This King Business: Collected Case Files of the Continental Op: The Later Years, Volume 2