The employer expects you to have a sense of where you stand in terms of salary. That also says something about you. Salary matters to everyone, so don’t say it’s not important, even if it isn’t the most important thing for you. Contact your trade union and ask about pay levels in your sector, or check the pay statistics online. Consider the appropriate level in relation to your current salary, your skills in the new job and the absolute minimum you will accept. Then make a proposal on that basis.