(Before that it was % 30 more ) offered salary is nearly lesser than my current salary.
I wouldnt worry to much about it, FX exchange rates are just a big game. The PLN will be back up at some point and then you'll be complaining the other way if you change now.
I get paid in many currencies and at the moment i try to insist on the Euro if possible. Its a strong currency at the moment and will be for a few years imo.