It has me curious, so I wandered the internet a little and found a Wikipedia entry, a Youtube review, a Wiley Clapp article, a couple of mentions by lesser known gunwriters, and two for sale stateside, one for $700 and one for $900.
Also this little tidbit: according to one of the articles, the BDM was developed in hopes of getting a contract with the FBI. When it wasn't selected, the gun was offered commercially only in the USA and Canada, nowhere else.
Any comment I saw from someone who actually claimed to have one was overwhelmingly positive.