Seems to me that it is market hype or "hubris" that supports the price of many places. People buying property off plans, maybe they never see it, maybe they never stay there, its hard to travel to or to rent or a managment company takes the lions share of it.
While I'd be willing to have a punt for maybe 70k if I had it handy (I dont) I get the feeling that there isnt brilliant "intrinsic value" in some of the property, and people are hoping there'll be another return hungry investor to take it off your hands. In this respect could it be a bit like a pyramid scheme, in that if the supply of return hungry investors dries up, are you left with anything of value??
The corollary of the above is that if I was going to spend big money I'd make sure I could get to use the property so that if the market dipped I'd have something of value and my funds wouldnt be in vain, I could stick it out for the long run.
To sum up the above ramble - I fear that many overseas property investors are strictly in it for the quick buck and think they might be at risk (either to cashflow problems or negative equity) if they have to ever fully pay off the property, because they have paid well over the "intrinsic value".