There is actually a LOT of margin in counterfeiting textbooks.
Even in the US a textbook costs ~$10 to manufacture. The reason prices are so high is that there's a high fixed cost up front to write/edit/typeset/design/market the book, and a small, capped number of readers over which you can hope to amortize those costs.
If publishers need to sell for $200 to break even, you can sell your counterfeit copy as "used" for $50-100/u, and get a 4-900% gross margin because you don't have to waste money on things like developing or marketing the content or paying royalties.
Even in the US a textbook costs ~$10 to manufacture. The reason prices are so high is that there's a high fixed cost up front to write/edit/typeset/design/market the book, and a small, capped number of readers over which you can hope to amortize those costs.
If publishers need to sell for $200 to break even, you can sell your counterfeit copy as "used" for $50-100/u, and get a 4-900% gross margin because you don't have to waste money on things like developing or marketing the content or paying royalties.