Amazon, AbeBooks, and Chegg have used 10th edition copies for as low as $9.99 + shipping. The PDF is not sold separately, but renting the physical book for a semester costs ~$25.

If you cannot access the PDF, here is a detailed, original summary of every major concept from the 10th edition – written as a study guide.

If your library doesn’t have it, request it via ILL. They’ll scan chapters or lend the physical book for free. You can then legally scan one chapter at a time for personal study.