@superuser: Check this article metrohouse.pl/?idNode=135&newsId=496
Here you have comparison of profitability of this business in various cities. Katowice is on top. (it doesn't take into account potential for price growth in those cities)
Basically Poland gives one of the biggest returns from rent in Europe, so it may be a good idea to invest money in such way. There are even companies which manage your apartment. They would find tenants and take care of the apartment for some fee, so you don't even have to live in Poland.
@inWrocław: Yes I know about Berlin. On average it has higher apartment prices than Warszawa or Wrocław, but it's a big city, so differences between neighborhoods can be bigger than in Wrocław, and thus some apartments may be cheaper. That's why Berlin's houses seem to be better investment than Wrocław's or Warsaw's in the long term. Prices there increased substantially in recent years too (because of low interests in eurozone). Berlin still has 2 x lower apartment prices than for example Munich, because it pays little and has relatively big unemployment when comparing to other big German cities. But this difference should disappear in the long term as it has been disappearing until now. And that's true that Polish construction quality, not to mention design land management lacks greatly to Germany.
That's why from financial point of view immigrating to Poland has no sense. Also German nature is very similar to Polish, as it's neighboring country. So it has sense to choose Poland over Germany only when it's about people. And perhaps it's not Wrocław being expensive, but Berlin being cheap.
Sale of apartments under construction rises
37% of apartments bought in Warszawa, Kraków, Trójmiasto, Poznań, £ódź will be finished in more than 1 year.
Amount of not sold new apartment increased by 8% although.
Apartment prices September 2014: