Try a search of the net, or ebay.
It was a group of Canucks that published it so should be plenty around your side of the planet.
Personally though I think the $50 is a bit steep for something that is way out of date for the interveiw process that is in place now.
Just do some research of EK on line and read the "How to ace the technical quiz" book. There isn't that much emphasis put on the tech side, more on how you interact with the others in your group and the facilitators.
Know how to fly a sim on raw data and keep the blue bit on the top and the speed and headings accurate.... but then that seems to be optional lately.
Good Luck.