As much as I do enjoy a good death in a story line... 
...I'm gonna pass on that one... 
The legendary thing is also a no-go. However, I do like the idea of a black market in general... 
Get those "Rare Candies" in circulation. 
Hesitation there would be figuring out what kind of stuff they'd sell, what kind of stuff they'd buy. Like, from a game-play perspective, using the shards there is fantastic, but I have to ask, what would people in a black market want with shards? 
Balls it, what does anyone want with shards? x.x