You work only for money. But many hesitate or don't know how to negotiate for salary. You need to present yourself well before prospective employer. Here are some tips-
https://in.finance.yahoo.com/news/4-most-powerful-salary-negotiation-150200065.html
A very informative article about which every job seeker should know.
There is nothing wrong in asking for a higher salary provided you present yourself with substantial reasons. Don't exaggerate about yourself. Negotiate in a sincere and straight forward way and stop. Let the evaluation part of you be left to the persons concerned.
@gkajmani