Don' t worry about it!  Redemption is easy.  Anyway, you haven' t even gone to the first interview yet!  Once you know more about the job and how well your qualifications fit the requirements of the job, you can easily adjust your anticipated salary, but not on the basis of some illusory "market rate," but on how well your qualifications for the job match its requirements.   If you receive an offer that you' d otherwise be happy to accept - accept it!  Never try to negotiate more money just for the sake of negotiating.  If you honestly think the salary is low, just politely ask if the offer is negotiable.  If it is, counter with a salary range in which you need to be, one that' s at least 10% to 15% more than you' re earning now.  Don' t worry about  the "market rate" for jobs like this one.  You' re one individual with one set of qualifications being potentially considered for one job with one set of requirements.  The basis for your negotiations, assuming you think the offer is low, is to say that now that you have a better understanding of the job and it' s requirements, your anticipated salary would be in the $X to $Y range, and see what happens.  Make sense?