I agree based solely on household income, affordability, cap rate, vancouver's prices are out of whack.
But I also think housing price is a lot more complex than simple quantitative statistic like average household income, interest rate and affordability, etc.
Many cities have affordability index much worse than vancouver, yet they have been like that for decades. (
Property Prices Index 2016)
Qualitative attributes such as cultures and people's perception on value plays a big role in market pricing as well. (edit: I think this is the part 4444 never considered)
Btw, i think during the US financial crisis, the average housing prices only fell 30% (while the stock market fell 50%)