Is it expensive to maintain a turbo car?

I've often heard that turbocharged cars can be quite costly to maintain. Could you elaborate on this? Are the maintenance costs significantly higher than non-turbocharged models? What are some of the common issues that turbo owners tend to face? Is it a matter of regular maintenance being more frequent, or are there specific parts that tend to wear out more quickly? Also, how do these costs compare to the potential performance gains one might expect from a turbocharged engine? I'm curious to understand if the added expense is justified by the increased performance.