Of course since the purchased capital never leaves the WT they are lying to say that they need to maintain the kingdom hall fund - all that happens is that the WT becomes wealthy at the rate of land appreciation, plus free labour and materials and then finally receives the cost of the hall plus interest back. So that's a doubling of wealth + free labour + rising land values + land improvement value + interest. Very nice. Still the LDS used to something similar in the UK but now we just get given a new building.