Actually you (or the Polish economy) will lose the money I spend in Poland that I earn from outside of Poland. So technically you are WRONG...again.
Whatever you spend will not be enough to make up for your presence in Poland. That is of course if you earn any money at all from outside Poland. If you earned decent cash you wouldn't be wasting your time scratching round the schools here trying to pick up lessons at any pittance of an hourly rate. Most likely you mean that you spend here the money that your mommy and daddy send you.
vaneck: as long as your TRC is valid and you have enough time on it to apply for another one, you'll have no problems at all at immigration.