Instructors can get complimentary examination copies, as well as copies of related teaching materials, from the relevant publisher.
For any of the five versions of my principles text, the person to contact is Brian Joyner at Thomson (recently purchased by Cengage). His email is email@example.com.
For my intermediate-level macroeconomics text, the person to contact is Scott Guile at Worth Publishers. His email is firstname.lastname@example.org.
If you would like a copy and are not a professor eligible for a free one, you will have to rely on the invisible hand of the market to meet your needs.