One cannot find a pill of such grade in the market as each and every one of these is a treasure that would either be in the possession of an alchemist who kept it for their research or in the treasury of a powerful clan.
In terms of potency, it almost perfectly retains the potency of its ingredients and is extremely; no, exceptionally difficult to refine.
For a pill of Heaven grade to be refined, the chances were extremely low, one could even say that it was next to nil. It was common knowledge among alchemists that one cannot refine a pill of Heaven grade during a normal refinement.
Pills of such grades aren't created, but appear through sheer coincidence and accident. It is when an alchemist attains a burst of enlightenment during his refinement, that there is a possibility of a heaven grade pill being formed.
