I don't want to move there and struggle to get by.
Unlike most Poles? What makes you think you should earn twice the average local salary, when you can't even speak the language, and are probably doing a job a Pole could do just as well?
4,000 zl a month is close to breadline in Warsaw. 6,000 is a more realistic.
African breadline, or western European breadline? I know plenty of people in Poland who earn less than that, and they manage to go on holiday, run cars, etc... hardly "breadline" wages. If you want a western lifestyle, move to the West!