[Louie grins and nods, quite pleased to see someone willing to shell out some money for the product. And, as any good conman would, he's already planned for a question like that.]

The well this stuff's drawn from is enchanted! It's actually on school ground, but only the professors have access to it - normally. I have an in with Professor King, so she gave me some, and I'm happy to share it! You know, for a price.