Salary negotiation in Abu Dhabi without losing job?

How to negotiate salary without losing job? I hade this email from employer (quoted below )and I need Your help to deal with it since I'm scared to lose a job opportunity if I ask for more salary. "Quoted" Thanks for having come over for the interview. We are close to reaching a decision on selection and are now putting together the screening observations. One thing we brought up during the discussion was clarifying on expected salary package. You clarified that your expected salary package is AED.15,000 (total of basic & all allowances). After reaching this stage, we have ascertained that our total salary would not exceed AED.10,000. Let us know if you would agree to this figure ( inclusive of basic and allowances for accommodation, housing, vacation air-ticket etc), should we decide on selection and make an offer to you. Your opinion is highly appreciated!