But you can negotiate other items to compensate your salary "loss" if you pretty sure you are the top candidate. For example, relocation of $xk, signing bonus of $yk, paid vacation of x weeks, work at home x days a week, company to pay for agent commissions if you need to sell your house, etc.
If you are one of the top candidates and this job is the only one you have at hand, I'd be very flexible until I get a firm offer.