With these things it all depends on the basket of goods used to decide on how expensive a city is. It could include golf club membership, private school tuition fees, a new Mercedes and a chauffeur. This might bear little or no relation for the actual costs of a real person living in a city, even for most expats.

I once had to help research a similar survey in Kyiv which would be used to help calculate cost of living allowances for expats (and was naturally encouraged by expats to hunt down the most expensive dry cleaners, tennis balls, microwaves etc etc!).

Of course there are certain things left out as well. For example I believe with this recent survey, the cost of an underground train ticket in Moscow (which was much, much lower than most other cities) was not included. The excuse was that 'expats would never use the Metro in Moscow'

So take any of these surveys with a hefty pinch of salt (unless it means you will get a more generous hardship allowance or cost of living expenses ) Yes, Moscow can be pricey at times, accomodation and housing in particular, but it need not be the most expensive city in the world!