From Longman Dictionary of Contemporary Englishbreak the bankbreak the bankto cost a lot of money, or more money than you have A new hard drive doesn’t have to break the bank. → break
Examples from the Corpus
break the bank• Attractive bathrooms need not break the bank.• I had no choice under the circumstances, and the fees won't exactly break the bank.• Shakespeare market a very good one through tackle dealers at a price that will not break the bank.• Should Johnson return to the Dolphins, he will break the bank.• At under £14,500 it won't break the bank either.• Don't worry about breaking the bank either.• I would like to gather everyone somewhere warm and appealing to all ages and not break the bank in doing so.• Last year, Courtney broke the bank with seven out of eight predictions panning out. 