With wizards is it often useful to buy a scroll of a spell that is a level higher than they can't currently cast, and use it if needed, risking only a small spell failure chance.
But alchemists can't use spell completion items like scrolls, and I thought I read that wands for "spells" that only appear on alchemist's extract list don't exist because they can't craft them without a caster level and wizards don't have access to spells of the same name.
I'm not sure if brew potion has a similar limitation, or if potions and wands both exist via the assistance of master craftsman.
What I'm really looking to determine is if there is any way that a 5th level alchemist (who normally only gets extracts up to 2nd level) can obtain a 3rd level extract, and somehow use spell slots and the infusion discovery to make infusions for other party members.
Basically is there any way to supply such items to the rest of the party for an average cost that is less than buying potions.
The spell in question is on the wizard list, so wands and potions are possible, but I want a use-activated item for non-casters and I'd like to know if there is any more economical way than potions to accomplish multiple castings.
AFAIK there is no way to do this. Items that increase your caster level exist, but I don't recall any that increase your class level or open up higher level slots. Metamagic rods could get you a higher level spell but I don't think those work for alchemists and even if they did they don't give access to spells with higher base level (only modify level of spells you can already access).