It's a double-edged sword.

Meaning

It has both advantages and disadvantages.

Examples

• John: 'Increased advertising might boost sales.'
• Alice: '<b>It's a double-edged sword</b>; it could also damage our brand image if done poorly.'
• John: '<b>It's a double-edged sword</b>; it could reduce our profit margins.'
• Alice: 'Lowering prices might attract more customers.'