Need to verify the current availability. Maybe the 8th edition is available on certain platforms. Let me think: McGraw-Hill offers access codes for their books, which can be bought separately from the physical book. Sometimes these access codes are available at lower prices or can be shared among students (though sharing is against terms of service).

Check if there's an official PDF version for purchase through the publisher's site or platforms like VitalSource. Some books are available as e-books through rental services. That's a legal way to access it cheaper than buying a physical copy.

I should mention that while the free PDF is against copyright, there are resources available through libraries. Maybe mention Project Gutenberg or Open Library as examples, but check if they carry it. Alternatively, using interlibrary loan systems.