It's not possible due to security reasons: if uber items would be tradable, it will be less more secured, because one stolen account means your items are wiped out in an instant..
Once bought or rewarded, those uber items stays in the same account, for that same reason: security.
You can only sell uber items within BTA which is directly assisted by the owner.
In my opinion, this suggestion doesn't have any kind of sense.
/Closed.