A fool and his money are soon parted
Definition 1 of 1
Pro Tip 1/3Impulsive Spending
This phrase warns against spending without thinking. It implies regretful decisions in buying. 
He bought another expensive watch, and a fool and his money are soon parted.
Pro Tip 2/3Financial Wisdom
Use this phrase to suggest learning about managing money better or seeking advice. 
She never budgets her expenses – a fool and his money are soon parted.
Pro Tip 3/3Colloquial Warning
This phrase is often used casually to warn friends or family about their spending habits. 
Buying a fourth car? Remember, a fool and his money are soon parted.