Hey all,
I've had some questions from people individually through tickets and forum PMs on this subject, and we want to let you all know about it.
There was a bug with the last LE set where only 2 of the 4 needed to be purchased to get a bonus unit. That being the case, we opened this set up so that everyone could take advantage of that same deal this week.
For future sets, we're going to continue to experiment with the bonus (it may go back to 4, it may be 2 ,or something completely different down the line), which is pretty exciting.
-CJ