A lot of printers usually over run the print order, we order 5000 a month and have had anything from 5400 to 6500 delivered to us. We get them bundled and folded into piles of 100, that's how we know the print is over run.
It wouldn't surprise me with the quantities Lee orders if his print run is 3 or 4 boxes over, so it probably balances itself out even with the throw aways.