How many alchemical items can a character create during the carousing phase

On pg 19 of Conan the Thief under Common Poisons there is a mention of Wealth level in reference to purchasing poisons. Is there something in this book or any other that references cost for purchasing alchemical items. I know the core book says that they must be made but then I see references to purchasing them as well.

As for the subject line, i would like to know what is expected of an alchemist as far as how much of his preparations can he make during the Carousing phase and how much can he have ready since the game seems to read like he can only have one preparation available between Carousing phases, unless I am misinterpreting or have missed something, please let me know if this is the case. Thanks.