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]
(..) what is this? Its a letter he wanna make you his assisstant or after years you will be in hospital and you will think that i could try it why you buy so much expensive? I dont wanna be a engineer i dropped from the rd floor of that building i did pee on director's office door while i was drunk (..)2009 3 Idiots