Although it says unopend and not tampered with etc i'd advise people take a good look at some of those pictures.
"Property of Microsoft" label <-- look at this one in particular.
From what i'd say it deffinatly looks like it HAS been tampered with on this label at some point in its life, please proove me wrong.
Also, the DVD bezel IS the wrong one, the official XDK bezel on such a unit should have green text, this looks to me like a crystal xbox dvd bezel in its place.
The unit if its not had anything changed is a DVT-4 development kit, as such the above should be correct, so the DVD bezel is wrong.
It would be nice to see a photo of the back of the unit to see what its like behind, i assume the extension cards are in place and as they should be.
I'm curious though, as ive seen too many re-builds of people putting xbox motherboards in the XDK cases and selling them as a genuine XDK, the sticker issue worries me. I'm not saying yours isn't genuine, but this sticker thing is a real worry for me.
Sorry to come accross probably in the wrong direction, but i'd just like to speak the truth and give friendly advice.
EDIT: Just to clear things up, the XDK's that had a different style jewel on top are the DVT-3's all XDK's came with the green text on the bezel, wether its a DVT3 or DVT4.