“Let me get back to you” has saved more people from bad deals than any comeback ever has.

Most regrettable agreements happen in the first thirty seconds, while you are flustered and trying to seem easy to deal with. A short delay costs nothing and breaks that spell. You are not refusing, so the conversation stays pleasant; you are simply moving the decision to a moment when you can think. Clever replies protect your pride, while a delay protects your month.

Memorise one phrase and use it on the next ask, even a small one. Let me check and get back to you. Then genuinely get back to them, which is the part that keeps the line usable.