I think most people believe salary surveys tend to run higher than real-world salaries, for a variety of reasons to numerous to mention.  What you need to do is come up with an anticipated salary range within which you want to be.  One way to do that is to propose a salary range that' s AT LEAST 10% to 15% more than you' re earning now.  Another way is to figure out what your average monthly expenses are over the last few months, and then take that monthly average times 12 to come up with an annnualized income stream you require and below which you cannot go and still pay the bills, make ends meet, and at least maintain your present standard of living.  Call that annualized amount $X.  Add about $10K to $X to come up with the top of your range.  Call it $Y.  Then see how this range compares to the 10% to 15% range I described above.  You may never have to tell anybody what either range is, but YOU need to know what they are so you can make a more informed decision on any salary offers that come your way.  "Market value" is such a nebulous term.  Each of us have strenghts and weaknesses relative to the jobs for which we' re being considered and, ultimately, it is the prospective employer who gets to decide what a particular job is worth to his or her organization.  Your challange is to be able to show how your qualifications for the job are a great match for the requirements of the job.  A reasonable starting point for you, assuming you' re asked directly what your salary expectations are, is a range that' s at least 10% to 15% more than you' re earning now.  If it turns out that the job requires more or your qualifications are a perfect fit, you can always adjust your range upward.  Hope this helps.