With the right kind of players, this can be an interesting plot hook.
Though, the mechanism of wish-granting could be subtler in some instances - at time it reads like a marketplace ("What does a leg get me?"); also, I can envision it sticking longer to one wishing person who has a great dream, helping him but consuming him in the end.
Plot hooks are good.
All in all, a good sub.
Very clear guide on what price is paid for each type of dream. I like Echo's idea of the mist helping an individual with a huge dream -- perhaps destruction of a whole race/kingdom, or something similarly epic. It could follow him around, sticking to his flesh as parts of the plan fall together in stages, the man losing more and more of his sanity as time goes on. With the mist billowing out behind him, he'd probably be heralded as a mad prophet/sage/wizard and gain a following.