"Oh, my embroidery comes with a full twenty-eight years of memories of living on an entirely different world. I have no idea who or what I was before I fell in the magic. It's been pretty useful, though."
"I know it makes people nervous. That's why I test new things on myself or animals first, and then pay people to try the first doses of anything new. At any rate, if you don't mind I'll be back in an hour with some morphine and hang around until someone wants their teeth or a cut done. I'd like to observe the effect."
So she goes to the shop and runs the numbers on the ingredient cost and processing time to decide morphine's price, and then comes back to the surgeon's place with a jar of little dark blue pills and waits for someone to want surgery.
She rattles off the risks and cautions to the patient, confirms that he hasn't been drinking or had breathing trouble, and says, "I'd like you to say out loud that you want to take this."
That wound is fairly nasty. The absolute maximum safe dose would be six - She gives him three pills. "It'll take a few minutes to kick in." And she takes up a position well out of the way to watch.
Once the stitching is done and the surgeon is cleaning up, she asks the patient, "How're you feeling?" (He should be feeling woozy and lightheaded, and not in pain)
"Yeah, that sounds about right. You'll want to stay here for a few hours unless someone can help you get home. But it doesn't hurt, right?"
And she asks the surgeon, "I don't want to sell this stuff unless someone actually needs it, it can really mess you up if you take too much or if you take it for a long time, but can you see a lot of people wanting it?"
"It's pretty expensive to make, unfortunately. I was thinking one and a half seo per pill."
"They'll keep for a year, maybe two. Tell you what, buy twenty pills at a time and I'll drop the price to twenty six seo - 1.3 each."
"Pretty linear, yeah. Two pills probably would have done well enough for him, one will do for scrapes. I'll draw up dosage tables and wearoff times. And you can stock some of my aspirin for after-pain if you like, that's much cheaper."
"Hold on, let me do some math." She does some math. "Seventy seo for fifty pills. I won't go below that, I'm getting pretty close to ingredients cost now."