Hopefully, this question is being asked of you upfront, and not during your second or third interview. Depending on the interview stage, your answer may vary.
Salary negotiation is real and sometimes an intimidating topic for interviewees, primarily if you have not yet established a sense of trust and rapport with the interviewer. Are you interviewing for a position that you know pays less than what you currently earn? Maybe the selling factor is that there will be less time to commute, weekends off and more time with your family, or less responsibility and decreased stress. Sometimes these reasons mean more to you than the bottom line.
"Currently I'm making approximately $20K more per year than you are offering for this role. I would be open to negotiating salary with you; however, at this point, the gap remains too significant. I am open to creative compensation packages such as added vacation time, better health benefits, or a car allowance."
"For the right opportunity, and better hours, I am willing to discuss a few options; however, my overall compensation including benefits and perks need to make sense to my career goals before I would make a move."
"I understand my base salary is $15k higher than what you are offering, so I am willing to look into creative solutions if the overall earning potential is there. That is, I'd love to hear what kind of equity you can offer, as well as a guaranteed year-end bonus. I do not doubt that I'll exceed metric expectations, and blow you away, and look forward to figuring out a compensation structure that would be beneficial to both of us."
"I'm motivated to come to your company and exceed expectations. That said, I need to ensure that with the added responsibility of leading a junior marketing team, that my pay commensurates with these new tasks and effort. I would be open to learning more about your compensation plan and how we can make it a win-win for both parties."
"From what I understand, the hourly wage offered here is less than my current position, but your commission percentage is higher than I currently earn. I would like to learn more about your metrics such as average purchase value and items per purchase before I agree to any cut in my hourly wage."
"I could only take a reduction in my base pay if my overall spending is lower in this new role. For instance, if you offer a counterbalance by way of benefit premiums, gas costs, mileage, cell phone allowance, and more, then I am more than willing to discuss some options with you."