Numbeo is a database of information about cost of living, quality of life, health care, pollution and crime, and other indicators of the living conditions around the world. The data is contributed by more than 150,000 in more than 4,400 cities worldwide.
For example, in the cost of living category, you can input two cities to get a comparison. I tried comparing Tokyo and Los Angeles.
As I suspected, fresh vegetables and cheese are much more expensive in Tokyo. Rice, too. And cigarettes are cheaper here.
The site should probably not be your only research source, but it’s another one to add to your toolbox.