Numbers and facts from me from 2013. Our family owns farmland on a gentle slope. Leased out for next to nothing. Not worth mentioning. The municipality wants to designate it as a building area. In the first section about 35 plots. Partly sold through the municipality, partly through an investor. Long discussions, complaining neighbors, eco-activists, etc. Later we all agreed. In the end, we sold for 68 euros per sqm. Selling price after development by municipality and investor was 295 euros in the first construction phase. In the second construction phase then for 340 euros. The last construction phase is coming up in 2023 with prices around 450 euros. About 47% of the gross area was actually sold in the end. The rest were streets, green spaces, rain basins, playgrounds, etc.
Without the involvement of the municipality, especially in the above-mentioned public areas, the investor would NOT have bought more.