Or they could provide a better product for that market that made it naturally distasteful to the US market. Like a book written in the language of the land (The market for CS books written in Filipino should be relatively small in a non Filipino speaking countries). Why make them work when we could just legislate profits their way?
The issue is significantly more complex than "legislat[ing] profits their way".
It's very unlikely that the discounted overseas textbook market constitues a very large amount of profit. Indeed, it could certainly be seen as reasonable CSR project: "Let's sell our books at marginal cost+10% to poor asian students, but have legal make sure those copies can't cannibalise our domestic market". If it turns out legal was wrong, the response is more likely to be "though luck, the global price is now $100" instead of "drat, let's lower the US prices to $20".
Now, being nice, even charitable, should not be a ticket to get to write your own laws. But Wiley is unlikely to celebrate a ruling of global first sale doctrine by convening an editorial committee to produce a Filipino CS textbook (and a dozen other languages times a dozen other subjects), to then go and sell that at $20 there.
Also, on a tangent, as the lingua franca of CS is English, it's convenient to learn the subject in English. I was taught CS mostly in English, but one time where the teacher insisted on speaking Danish, it took me half the class to realize that oversætter (literally translator) was meant to describe a compiler.
