There was a hack for this in the past, however, I doubt such an item will ever be available to the public through legitimate means.
I would be willing to pay over 100k NX if it were added in the CS though.
I'm not so sure. Think of all those RED weapons people have. I mean now since there are so many ways to get Unique potentialed low level equips that are at least third tier it'd be well worth the wait to hold onto all of them and keep them.
It's like like a free Unique scroll except you're paying for it. Would probably cost a lot though.