Perhaps Harry or another resident of Warsaw can tell us about the kind of money that lives in Żoliborz.
Working from the size of the balcony door in the photo and using that to estimate the size of the windows and thus the length of the front wall, the front of each half of that villa appears to be about 8 metres wide. Using the 'twice as deep as wide' rule for semi-detached houses, we can assume it's 16m deep and thus each floor is 128 sqm. It's three floors, so 384 sqm. In that area you're looking at a minimum of 10,000zl per sqm. That place looks to be in slightly below average condition but it actually isn't, it's had some very very expensive work done to it, as said in gregy took that photo from, which is why he didn't link to the article; anyway lets' say 10,000 per sqm: that's about 3.84 million zloty. I seem to remember that Polo says that assets of over 3 million zloty is "a staggering fortune by Polish standards".
a villa in Żoliborz costs a considerable amount of cash.
Actually, the house that was built for AK officer turned educator of the elite, Rajmund Kaczynski, would be worth more as an empty site, the ground there would be far more valuable than that house, were it not for the very expensive work done on the house. But we're as likely to get answers as to how Rajmund's son funded that work on his MP's salary as we are to get answers as to how Rajmund rose so far and so fast without being a turncoat traitor.