The $9.99 jewel case Deus Ex at Target is a "Special Limited Edition", which means "Demo". I made the mistake of buying it, as there was nothing on the case that indicated that is was a demo.
Target would not refund the purchase price, due to copyright laws for opened software, even though it is impossible to tell that this is a demo until after you start the install program.
I have talked to Activision and Eidos about the packaging, and they all wanted to pass the buck to each other, although the Eidos guy did promise to 'talk to his supervisor', but I'm not holding my breath.
I picked up the full boxed version at WalMart for $20 instead.