When an item gets patented by Welch and it goes onto market, a random max number of that item is added to the store stock (the rarer the item, the less are usually up for grab).
So apparently, they figured no one was going to buy that much Ressurection Elixir so they only have 6 available >_<
Fastest way is to use Compounding and make the remaining 14 Elixirs
