It certainly depends on the industry. I.e. here in Russia if you work in the oil industry you would be making mad amounts of money. It is hard to get into, however, and you would have to live in middle of nowhere, Siberia for years.

Not quite sure about subdivisions in tech - i never worked for any buzzword "all the rage" things. I suspect that if you are a rare expert in a field with a lot of demand, you would get a good income regardless of the level of buzz.