I understand there might be reasons to not want emblems, cubimals, and other things auctionable, but the reality is, people will trade or sell them regardless. And when they do, they spam global. Just now, the same person has been advertising emblem trades/purchases every five minutes on global chat. This is ridiculous. And shouldn't be necessary.
If you don't want items sold, set up a trading post so that someone can post an item (or items) and specify that they want X number of X item(s) in trade. If someone else offers up the desired trade items, the trade happens similar to an auction item being purchased. I have seen a similar thing in another game, and would be happy to point devs in that direction if they wanted to see it.