Like I said before, marvel steels are very strong in popularity and value. They will not go down. Iron Man Play.com, even IMO no where as good material quality as the Future Shop version (impartial opinion), is steadily rising now.
Thor and CA HMV UK's are now bidding over £100. BIN are always more than auctions and already listed for £150 BIN. I reckon these will sell for £150 by the end of the year and top off Star Trek and become the UK grail
I say the next grail will be Phase 2 of the Marvel Avengers releases. The only thing to slow this to be a grail is you bet studios will profit on this opportunity to make as much money as possible and there be a world wide release as always.
So it goes back to the slips and stickers. Which Asian country can make the run limited with a fancy slip? That will be the next grail IMO