Not a bad idea. Though you could've been a little clearer with the topic.
Opened the topic just because of the confusion regarding readd. Should have typed it "Re-Add" instead.
I think the problem, and I'm going off of assumptions regarding the boxes, is that they're more inclined to fail than succeed. It's like a casino: the house always wins, even if there are a few lucky ones that come out ahead, the house still makes more in the long run. The odds of a the boxes, or an NPC if it were implemented, handing out more than one puts in is likely to be less than 49% chance of success. If it were any higher, than it would lead to overproduction of crafting materials in the game, meaning essentially free item generation.
But who am I to stop others from gambling. They can get lucky, and that's all they want. I'd agree to this sort of NPC in the game, but I'd never bother with it unless it was tied to an achievement or something like it was already (6 successes in a row or something I think it was).
Better idea.
Tera lottery. There is an npc and every so often a lottery event comes up. Top prizes are really rare items and hats and cash prizes. Common prizes include engines and common dyes.
This also works with other contests that are a good idea to implement, such as dueling contests, treasure hunts, or holiday events.
Lottery is a fail design. Failed in Lineage 2 will fail in tera.