A Source of Revenue?

I finally got around to reading Daniel Wolfe's article about internationalisation, but this is what confuses me, and always has, regarding the recruitment of international students to Canada...

"I think the reasons for internationalization are many, and bringing in extra tuition revenue is one of them, undeniably (international undergraduates, other than exchange students, pay increased tuition to reflect the fact that there is no government operating funding provided for international enrolment)."

If the government isn't contributing any funding towards supporting these students, then surely the extra tuition we charge them doesn't really count as "extra" because it's money that the government would have provided (had they been domestic students)? So in effect we charge them more because they cost more? Unless they are really scalping these students and adding huge amounts to their tuition (i.e. a lot more than what the government would provide), then this doesn't sound like a revenue stream to me. But perhaps that is what they're doing--I'm not sure (please answer in the comments if you know!).

International students often require special resources above and beyond what domestic students usually need, so there are other costs that detract from this "profit" as well.

And if Canadian university expansion occurs to accommodate more international students, what will happen if and when those students' "source countries" develop the capacity to educate locally? Unless of course we just want to keep exporting our Western Brand™ of university education and never expect those countries to develop their own "knowledge infrastructure". I just get the sense that we're trying to use these students to shore up gaps in future cohorts that we know are going to decline, because of demographic trends. We are still treating these students as a "market" and markets fluctuate; are we actually planning for that or are we just heading into further financial sketchiness?