Kiaane, who very much forgot whether to ask their recipient if she's allergic to any materials (including chrome, which can be present in leather), ellipses.
"Twine should be fine," they state. They don't sound that certain about it, but at least it rhymed.  
The narrator thanks her for her, uh, patience and accommodation. 

(What's adult you-know-who's neck circumference?)

(The heck is 'normal'?? Kiaane doesn't know normal and neither do I
Me not knowing necklace types hold on lemme Google
It looks like a choker is probably way too tight for something with an amulet hanging off of it. I'd say more of a normal necklace but tight enough that you have to put it on by linking the back or something. If that makes sense. xD)

"One string 50 centimetres, and the other somewhat longer," they request, pausing briefly to decide on the second string's length. "56 centimetres for the second," they clarify, "please." 

They shake their head. "Two more strings, please. Intertwined. Ratio to prior two strings should be 1.31:1." They hesitate and add, "A nice box would be nice."
A yellow car is yellow.

Kiaane nods like a little kid seeing candy, specifically the kind of little kid who isn't picky at all when it comes to sweets. They then proceed to take everything and try to put it together. Opening the box and briefly analyzing its structure, they put in both intertwined strands of twine and the amulet. 
Click.
They look back up, seemingly avoiding her eyes. "Price?" they ask.

Hey, that doesn't mean it's too expensive either. Right? ...Right?
Please Eny, Kiaane needs to eat. 

Kiaane doesn't seem particularly perturbed. Then again, they're quite hard to disturb, in certain senses. They give the box a hard stare.
"What is taking up the bulk of that number?" they ask, and decide to add, "The box, or the amulet?"
Imagine if it was the twine, lol.

They put the box down carefully, as if to show that they don't intend on being a thief.
"It seems somewhat overpriced," they observe, "considering its lack of conductivity." 

Well, this is a questionable decision.

"Not pertaining to electricity," they immediately specify, as if they're sure that that's the misconception that might have come to her mind. Then, for the rest of their response, they touch the tips of their index and middle fingers on both hands together. Upon pulling them apart, thin silver strands of some sort of magic spell are revealed to be intertwined between them.
...the alarms really don't seem to like whatever magic they do, huh. This time, though, Kiaane doesn't seem to notice or to care. Either way, the alarms are about to act out again, and the mage doesn't do a thing in reaction to them. They instead pull their left hand away from the readily glowing spool of magic in order to use it to open the box again, and then they lightly point at the amulet with their other hand-- probably not about to blow up anything, but a little caution goes a long way. 

Despite being the magic of someone who seems quite languid, the magic is fast. In fact, the way it moves feels a lot more like a spider moving in on its prey or a snake snapping outwards from a coil rather than the graceful flow that some types of magic exert in their movement. In a way, it fits the straightforwardness of its caster's speech--but in a way, it also doesn't. It's fitting.
But the narrator would be surprised if any of that was crossing Eny's mind, because it's not really supposed to for someone like her. Rather, what she sees is probably rather straightforward--a small spool of magic that is making its way into the amulet in a way that it probably should not be able to do, more like a parasite than anything related to enchantments. Essentially, still creepy, but probably not anywhere near the scale of what the narrator's imagining.
What can they say? This is lowkey concerning, but please don't do an identity check on Kiaane. 'Cause they really don't have an identity or proof thereof. Wait, is that a plot hole? Do magic item purchases require the purchaser to be a certain age?
As for Kiaan, they actually overdid their magic a little, something very uncommon for them to do. But it's just as well that it's their magic that's making them do so. They watch their momentary creation squirm into the amulet with a deadpan expression that doesn't indicate at all that they very much know that they messed up. 

"Nothing intrusive," they reassure as the magic unconvincingly finishes worming into the amulet. Averting their own gaze from the concerning phenomenon, they redirect their line of sight directly towards Eny, like what they were demonstrating has been demonstrated. Which, technically, it was, but the point probably hasn't actually been made. Their fault, lol. 

They center their gaze to look her directly into her eyes. "Customers can change their minds."
That came out kind of wrong.

Kiaane's gaze is more emotionless but somehow provocative rather than unamused. Intense, though? Yes. But thankfully, their words are more passive to contradict that feeling.
"As said, the measure was unintrusive. Only demonstratory." Yes, they just made up a word to not say more words. They lift their hand slightly, intending to demonstrate just that, only to put it down again, probably out of an abundance of caution.
"The fact remains that the amulet is overpriced," they add, possibly unhelpfully, "considering its lack of conductivity." 

"Precisely," they state, calm as a leaf. 

"Because this is imported?" they ask.
Regarding why she can't do anything about the price, that is.