Google Books has it listed. Amazon sells it for US$35. But Nitschke, interviewed for a story in today's The Sun-Herald says:
"We've heard there has been some trouble with buying it on Amazon ... from people not receiving books. We suspect they've been intercepted or something's gone wrong."
He also says it's "been a steady seller" on Amazon "often ranking in the top 1000 books in a pool of 2 million". But Australian buyers ran the risk of customs confiscating it.