It's in a "new" style Japanese version mono-colour box but instead of red and white the box is black and white. The Prime looks like a black version of evasion mode Optimus. It's been on the shelves in stores in Wan Chai's for months... Next time I'm over there if they still have one I'll see how much he is.
The second one I've seen hanging around is (I'm guessing) a one step Western Star black Optimus on card. The backing card is blue with Japanese on it.
I don't collect Nemesis so aside from casually looking at them for their deco's I don't pay much attention to their rarity so I assumed they were common. Sorry. :/