Yes, this edition is long out of print.
However a new, updated edition has been published in Spring 2002.
The new edition contains nearly all the original text but with additional commentary chapters increasing the content by at least 50%. Extra topics include Chaos magic, cyber-animism, sacrifices and demons, the New Age and Magic plus much more.
The new edition is available from Amazon as:
SSOTBME Revised - an essay on magic
by Ramsey Dukes
Published by The Mouse That Spins
"About this title" may belong to another edition of this title.
Seller: Reader's Corner, Inc., Raleigh, NC, U.S.A.
Trade Paperback. Condition: Fine. Austin Osman Spare (illustrator). 1979 Edition. This is a fine, as new paperback copy, 1979 edition, tan spine. 96 pages. Seller Inventory # 090861