One things for sure, if they were paying all those who were involved, even the minimum wage, the cost would be astronomical. If you had to pay those people you would soon be going backwards on the job. Good thing they are all volunteers.
The sites are always way to overcrowded with eager, unskilled juveniles, also with everyone working on top of one another it is impossible to work at a normal acceptable speed. In my trade, I would say that the work gets done at half the rate it should be done with the amount of tradesman involved. Half the speed at best.
Of course they will say KHs gettin built in three days is evidence of the Holy Spirit. They would never say that the mind control techniques are working wonderfully, and the cult personalities are making the Organzition a fortune.
The quality of the work I think generally is reasonable, but I have not really been involved with many.
They say you get what you paid for, and the WTS pays nothing....... so we shouldn't expect much.