One thing the Irvine Housing Blog reminds us is that the act of buying a house involves a large transaction cost. Real estate commissions are the big obvious part of this, though they aren't the only cost.
The broader point is that despite the rhetoric of many, home ownership just isn't for everyone. If you're relatively mobile, or think you might be, it isn't a smart financial transaction even if you expect decent appreciation of house prices over your expected tenure.
