There are thousands of other ways. But you have a bad attitude, why in the world would I tell you?
winning the Lottey, theft, selling organs, working very hard and saving, asking friends for an interest free loan, investing in Polish real estate from 2001, inheritance, become an MP.
Theres 8 please give a few of the other 992+.
However it is clearly insane to pay 650 000 pln in whole your life for a PROPERTY THAT IS OWNED BY THE BANK and not by you, until you finish all your payments !
Its the cost of borrowing money me old mate a concept which you obviously dont understand, what do you expect interest free loans? If you owned the property for five years and had equity of say 30%, you could sell and pocket 60,000 PLN, does that sound a little bit better? or plough that profit into your nest property thus bringing down the monthly repayments.