Money doesn't grow on trees.
something that you say which means you should be careful how much money you spend because there is only a limited amount '/ This means that you have to work to earn money; it doesn't come easily or without effort.
Son: Dad, can I have a newbike?'
Dad: 'We can't afford one. Money doesn't grow on trees, you know.'
Son: Mom, can I have $50 to go to a concert?
Mom: No way! Get a job! Money doesn’t grow on trees!
When the boy wanted an expensive computer to replace his old one his father said, "Do you think money grows on trees?"