My memory must be playing tricks again! I thought the price was £25, about $40, at the time. It is actually £40, which at todays (better) exchange is about $56.00. Still, it's a rare and interesting book and I would cheerfully pay more. If you are interested, here's the info:
www.motorbooks.co.uk
La Mula De Hierro - Columbia Rlys (With Summary In English) ISBN : 958 9044 263 Arias De Greiff 39.95 Pounds Sterling
Amazon.com doesn't have it, but their computer recognizes it as an out of print book and offers to search for you.
Enjoy!