your mayor sounds like a right sh#t!
Actually, you're completely ... wrong :)
He's a very nice guy, my school teacher back in the 80's, but he has to take care for the city, not for his ex-students.
I said mayor, but I meant the whole City Hall, there are several different departments, some make decisions about "planning" (planowanie zagospodarowania przestrzennego), others negotiate the prices with potential buyers/sellers etc. And the plot is quite small, so I guess he's not even aware of the whole thing,
Of course, the fact that I like him doesn't mean I'll sell for that price :)
and it's not that our City Hall is breaking any rules, that's how the things in Poland look quite often, if they changed the plot to "budowlana" and then bought it from us for a high price, they would probably run into some troubles with the surveillance bodies (like NIK - Najwyższa Izba Kontroli or Wojewoda), I really don't know what are the general guidelines of the Polish government, but I expect them to be not in my favour :)