This question evaluates your expectations, realistic or not, as well as your self-awareness of how this interview has gone so far. Your answer will speak to your professionalism, and therefore your professional worth. Educated transparency is the best route. Revealing how you've calibrated your suggested salary frequently serves as a strong performance indicator. One method is to contrast your current pay rate with where you stand on your career trajectory. Feel free to take into consideration bonuses and incentives. You could even factor in your commute, the job market climate, and any benefits you've had or are hoping for, such as medical/vision/dental. Be open, realistic, honest, and open to negotiation.