That's bizarre, isn't it? I wouldn't feel comfortable to pay $600k for a house which costed 'only' $300k in 2013. Especially when you need a mortgage for it. As the price of labour and materials only increased by 10 or 20% in that time, the rest is 'fried air'. The value can be halved in the next 7 years, leaving you with a huge uncovered mortgage. But I suppose you don't have a choice, when you live there.