Actually if you compare San Diego prices to cities such as Paris, London, Hong Kong, Shanghai, Barcelona, etc…, our prices are comparatively low — even more so considering the weak dollar.
However, it’s very hard to get residency. Foreigners do buy house for their children near university campuses. If you can afford the out-of-state tuition, you can get a student visa.
Property taxes and HOA in America are very high so the holding costs add up.
Foreigners have their own deflating bubbles to worry about. The difference this time, is that the bubble is worldwide, not just in certain local markets. I worry about a global recession if housing prices around the world drop by 50%.