Remember: it's foreign money, not foreign nationals. Citizens of convenience don't count as "foreign nationals" but absolutely trade in foreign money.

While I agree that tackling foreign money is important, don't underestimate the impact of local participation/debt. Will foreign money pick up the slack because first-time buyers can't borrow enough. Maybe, but I doubt it. 
http://vancouversun.com/opinion/columnists/douglas-todd-is-china-popping-vancouvers-housing-bubble

It's not usually foreign buyers who are buying townhouses in Langley for $750k.