For those of you looking for one where they "disappeared" from the store I have an idea. Check your local Tuesday Morning store. I found reissues there for $7 each when TRU had gotten rid of them. It may be a long shot but could pay off for you.
I got my black Energon Unicron for $15 at TRU I was just at a TRU today and I think they still had the new Unicron, but I didn't check the price.
dang , that is an awesome price...i sold mine off about a year ago and now miss him...need to replace him so i have the black unicron and the normal unicron side by side again...
He means when Unicron was originally released during Armada. That planet-eating bastard made Supreme Cheetor look like a bestseller, and sale prices for him were ridiculous.