With the latest patch everyone can buy Tionese commendation boxes for 25 tionese crystals.
Here if the trick if you want to be able to peek inside and change youre mind if you dont want it.
1. Fill upp youre inventory so you only have 1 slot open.
2. Buy a Commendation box. (now the inventory is full)
3. Open box, take all --> inventory full (now you still have the box with the item inside)
And the bonus is: the box is no longer bound for x days y horurs, and you can sell it on the Trade Market. ~20k each @ The Red Eclipse
Happy credit hunting.