I have done that before via base transfers! I may do it again sometime where people purchase additive traits as well as edits, if that was something you were actually interested in.

With trade-ins though, there's always the clause that it will be revamped even if I've not sold them, because it's still a 1-1 trade to me. ): so I don't think I'll do anything where people just trade in for a new MYO because if I don't like the design I really can't do anything with it and wind up with nothing in return.