It's only good if you come from the east, as their wages are even worse compared to their prices.
Even Google doesn't pay that well in Warsaw. You're much better off getting some sort of pseudo-b2b arrangement to a local software house. That gives you a ridiculously low income tax rate of 19%, too.
Of course, B2B contracts are event better, mostly because of lower taxes but they have their own disadvantages (often they can be terminated within a week, you don't have PTOs etc.)
Still less than what you can make working remotely for western European companies.