So, in total there will be 4.
The B/W variant cover you refer to, wasn't actually a mini-comic as far as I am aware. I think it was a print of the new DC comic (which is unrelated story-wise). There's a thread on here for those comics (tho I wonder if that thread should have it's own board, cause It's not really anything to do with Classics after all?)(Maybe that would cause less confusion?)