I totally agree with Morpheus. I also think that upper connected people (not necessary GB) are swinging funds to their family or buddies in land purchases, construction supplies, legal transactions, etc. on all this.
Money needs to be locked up in properties instead of liquid for reasons of lawsuits. But the new style for Kingdom Halls allows volunteers to pay for and build them and they will be easier to sell than the previous styles.
So let's review: WTS takes all the money, they look like they are spending it back into the membership, the membership continues to pay into the slush fund, buildings are ready to sell for at least no loss and probably a profit should the slush fund ever dry up in a particular area.
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Edited to add:
Maybe they have even copied close enough, a style of small business that is popular enough to sell. Heck, maybe they even are in cahoots with some people ready to put small businesses in the exact same locations should buildings come available. Like HHGregg stores moved into closed Circuit City buildings.