A good chunk of that is likely due to the desirability of Greek land. Based on a question someone posed in the prior thread I looked up real estate in Athens and stuff is expensive. Greeks who own homes are doing well based on the home prices.
I ignored the high end, luxury prices, but looking at South Athens, 1 bedroom condos were priced at ~200-250k euro dollars and 2 bedroom places were going for ~250-400k euro dollars. Some were higher, some lower, but those prices seem to cover the majority based on scrolling through a few pages.
http://www.homegreekhome.com/en/search/results/residential/sale/r102/m102m?ref=homepageMapSearchSR
That kind of value isn't quite at SF levels of pricing, but it is still some pretty valuable housing.
Out on the islands land is a little cheaper, but it's also more difficult to access.
One question that does come to mind (as an American) is why haven't Greek housing costs corrected themselves and taken a downturn with the economy? While the housing downturn was painful for many in the US who had overextended themselves, as the economy went down so did the housing costs, which ultimately enabled many others to be able to afford their first home.
Granted we had some extreme cases (like Detroit) where the value pretty much went to zero and that wasn't the standard for the country, but housing values everywhere did take a nosedive.
And as the recovery has come (stronger to the SF area because it dropped the least and started rebounding first) we're seeing similar things locally where people simply can't afford the cost of living and are being forced to move out of the area to places with a lower cost of living.