After bringing my alchemist Barbatos the Master Spellbook to upgrade my Alchemy Garden, I get a new conversation alternative from him: Do I want him to make me a spellbook potion?

He asks me if I want the potion to provide extra strength, extra dexterity or extra intelligence. He makes rather a big deal of it, and I also get the option not to make any potion at all ("maybe later"). So I'm thinking this is perhaps some kind of one-time offer only.

Is it? Or can I make all three of those potions?

(Is there even such a thing as a one-time only potion? I've heard some rumours of stat-altering potions before.)