Hmm that could be right, I don't have any MGS stuff but following auctions on Japanese site and they're going for a amazing prices actually all MGS stuff are valuable.
Just want to show an example like that. That's a AC Lighter:
http://www.ebay.de/itm/ASSASSINS-CRE...item35e1187a5b
seller told me that's 100% official promo item, but...
http://www.google.de/imgres?imgurl=h...ed=0CB8QrQMwAA
Not sure exactly that MGS lighter and items are same like that probably, just fake.