London: world's most expensive city

Google made me an offer, and part of that discussion included a link to a comparison of the cost-of-living in major cities. It's based on a basket of goods typical of Western consumer habits (see also purchasing power parity). London's markedly more expensive than even the second place city, Oslo. Dublin, one of Google's homes, is broadly similar to Zurich and Paris. Some surprises for me were Brussels and Sydney, both a quarter less than the Zurich benchmark! I thought they'd be much pricier. What's perhaps even more amazing is that you can live on a quarter of what you would in London, in major cities in Eastern Europe. Wonder how long that'll last...