Not that this data has ever been correct, but it's now missing entirely. For every single item hover, the "Price Today" and "Overall Price" both say "Not enough purchases".
It may be that it was recently reset? There are a few that have prices like
Dexter by ❤
Pinging you again, in case you missed the previous one. :)
Is that data something that gets reset on occasion?
[edit]
and - Just realized today that for at least some of the item hovers, the "Price Today" and "Overall Price" data is being pulled from the legacy shops instead of the new shops.