According to levels.fyi, the median salary in Google Munich is 147k USD [1] whereas the median for Warsaw is 82k USD [2]. Central Europe salaries are still quite a bit lower, even if you can be creative with taxes. Those B2B contracts are not quite as prevalent as one might think - larger corporations typically don't use them. And, from my experience, you can get to an even better take home pay with a little bit of time and career progression.