These seem a little too cheap:
(https://i.imgur.com/G9o8WWB.png)
That doesn't seem to be in her shop, so I think someone just sold it.... let me know if it shows up again.
They appear with a successful persuade check. See the bottom right segment of the screenshot.
Since they can be persuade checked, it is definitely a native item.. sold items never appear after a persuade check.
Should be fixed.