A penny for your thoughts
Your opinion or thoughts are worth something.

Break the bank
To spend all of one's savings or money.

Cash cow
A business or product that generates a steady return of income.

Easy come, easy go
Money that is easily earned can be easily lost.

Feather your nest
To enrich oneself at the expense of others.

In the red
To be in debt or to have a negative bank balance.

In the black
To be financially solvent or profitable.

Money talks
Money can influence decisions and situations.

Nest egg
Savings set aside for the future.

On the money
Exactly right or accurate.

Penny pincher
A person who is very careful with money and tries to save it.

Put your money where your mouth is
To back up your words with action or financial commitment.

Saved by the bell
To be saved from a difficult situation just in time.

Show me the money
Demand for proof of financial commitment.

Throw money at something
To spend money on a problem rather than finding a solution.

Time is money
Time is valuable, and wasting it is like wasting money.

Tighten your belt
To cut back on spending.

Win the lottery
To gain a large amount of money unexpectedly.

You can't take it with you
Material wealth has no value after death.

A dime a dozen
Something very common and easy to find.