THEY are so rare to get from a NPC drop THAT it SHOULD not really affect the amount of QSEs bought, actually it might actually raise the amount bought.

So if QSEs where trade able then players could buy them to sell to other players who need them and since QSEs cost so much, are so rare, and since the missions they would be used for are so awesome, the price for them would be REALLY high.

You can trade it just upgrade a planet for someone hehe

But you can't do the Dyson or Rift missions doing that....