break the bank
idiom

- to cost too much or to spend too much money

(Cambridge Dictionary)

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"Break the bank" has its origins in casino gambling and refers to when the casino bank does not have the cash to cover winning bets (to be "broke," past tense of break, means to not have any more money).

Bank is used as both a noun (among other things a place where money is deposited) and a verb (to deposit money somewhere) and can be found in several other common expressions:

- bank on it = to be so sure of something that one can trust it as one might trust a bank with one's money (I will be there on time. You can bank on it.)

- take it to the bank = able to depend on the truthfulness of a statement (We will win the league championship. You can take it to the bank!)

- laughing all the way to the bank = said when someone makes a lot of money very easily, often because someone else has been stupid (If we don't take this opportunity, you can be sure our competitors will and they'll be laughing all the way to the bank)

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Practice OWAD in a conversation today:

"If you take the time to look around, going on holiday doesn’t have to break the bank."