As soon as I uncovered the first locked module, I flung my money at the screen and bought them all. With my leftover, I first bought an epic chest. My second chest was just level 2, but when I opened it it had two epics in it, like an epic chest. I tried to do it again (epic then level 2) and it didn't reproduce.
That's not a bug. Every item has random rarity so any given chest could be nothing but Legendaries. If it happens too often - then we may have a problem.
I cannot possibly see how chest containing nothing but Legendaries happening too often being a problem!
