Stieg Larsson's
The Girl Who Kicked the Hornets' Nest is down to 99p at
Amazon UK.
The Final Adventures of Sherlock Holmes, also 99p at
Amazon UK
The latter's edited by Peter Haining and is basically a collection of Holmes-related items, mainly by Arthur Conan Doyle, that aren't part of the official canon, but which are still of interest. Two plays (
The Crown Diamond by Conan Doyle,
The Painful Predicament of Sherlock Holmes, attributed to William Gillette), a few short stories etc. There's a fairly thorough review of a 1995 Barnes & Noble edition
here.
The Theatrical Sherlock Holmes, another 99p buy from
Amazon UK.
This contains the two plays that are in the Haining volume, but of more interest is that it also contains the scripts to the original William Gillette play, and Conan Doyle's own adaptation of
The Speckled Band.