When it comes to spending a lot of money, "cost a pretty penny" is just one of the many phrases that can be used to express the notion. Other synonyms include "break the bank," "spend a fortune," "pay through the nose," "shell out," and "burn a hole in one's pocket." These phrases have been used for ages and indicate that spending a lot of money is not a new concept. In fact, it's something that we do often, whether it's for a necessity or a luxury item. Regardless of the synonym used, it's clear that spending a significant amount of money is not a decision taken lightly.