Her decision to leave the company proved to be an 'expensive' mistake. [=a mistake that caused her to lose a lot of money]
They live in an 'expensive' neighborhood. [=a neighborhood in which houses, apartments, etc., cost a lot to buy or rent]
an 'expensive' shop [=a shop that sells expensive things]
(..) I feel invincible. - It's midlife crisis. That's all this is. Here's my suggestion. You go out and you get yourself a big expensive sports car And a younger woman with questionable morals. That's what your father did, and it worked for him. What would I be without you? (..)2009 TvShow: Heroes Title: Chapter One 'Orientation/Jump, Push, Fall' Season: 4 Episode 1