the morgan stanley charts revealed - oh dear, page-83

There are 60 cities just in China with populations greater than 1 million... and China is not considered highly urbanised.

There are probably 1,000 plus cities worldwide with populations greater than 1 million(if that's what it takes to qualify as a city) - so I suggest a top 30 or top 20 ranking makes Melbourne and Sydney amongst the most expensive... the top 1% worldwide.