Will never happen.
You make 10 accounts, send them walking around, dueling, building church, dueling, fort fight, duelling, build church, build church, build church, duelling, fort fighting, fort fighting.... In 12 months, you get 1100 free nuggets (99,999% never understand why InnoGames makes sales at 1200 nuggets) on 10 accounts, just for login and 1-2 actions, per day. Buy 10 items and sell, for 5k to main account, And can make the set, level 2, for free. InnoGames knows that there are millions of those "slaves" (aka dobby scripted players that don't even remember they have 100 accounts working for an account, on each world) and making those items auctionable would only be another killer way for the game. Already happens in many events where the cheaper left hand weapon are $1M but main accounts get 27 right when they are auctionable. Then, for chance, the market has him selling 1 wood for $2.5M, same one sells 1 stone for $5M and bargain tobbaco for $10M. All sold in seconds, since they are so cheap.
Nugget items are nugget item. Not in any way they should be auctionable. Already so much multis around that would break, even more, any other players.