break the bank, to

break the bank

To be very expensive. The phrase is often used in the negative to convey the opposite. I don't have enough money to go on a vacation right now; I'm afraid it would break the bank. Here are my favorite discount options that won't break the bank.
See also: bank, break
Farlex Dictionary of Idioms.

break the bank

Fig. to use up all one's money. (Alludes to casino gambling, in the rare event when a gambler wins more money than the house has on hand.) It will hardly break the bank if we go out to dinner just once. Buying a new dress at a discount price won't break the bank.
See also: bank, break
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

break the bank

Ruin one financially, exhaust one's resources, as in I guess the price of a movie won't break the bank. This term originated in gambling, where it means that a player has won more than the banker (the house) can pay. It also may be used ironically, as above. [c. 1600]
See also: bank, break
The American Heritage® Dictionary of Idioms by Christine Ammer.

break the bank

1 (in gambling) win more money than is held by the bank. 2 cost more than you can afford. informal
See also: bank, break
Farlex Partner Idioms Dictionary

break the bank

To require more money than is available.
See also: bank, break
American Heritage® Dictionary of the English Language, Fifth Edition.

break the bank, to

To ruin financially, to exhaust (one’s) resources. The term comes from gambling, where it means someone has won more than the banker (house) can pay. It was so used by Thackeray (“He had seen his friend . . . break the bank three nights running,” Pendennis, 1850). Today as a negative it is sometimes used ironically, as in “I guess another ice cream cone won’t break the bank.”
See also: break
The Dictionary of Clichés by Christine Ammer
See also:
  • break the bank
  • count for
  • count for (something)
  • be (not) as black as (someone or something) is painted
  • (not) give a toss
  • (not) give a fig
  • (not) care a fig
  • fig
  • caring
  • (not) care a hoot