In-game human leather says it has a market value of 300% (compared to most other leathers at 130%). But it doesn't seem to have any effect on the value. I crafted a Human Leather Duster (Normal Quality) and it has a market value of $815. But a Muffalo Leather Duster (Normal Quality) also has a market value of $815. Both are at 100% health; no damage has been taken by either of them and they have never been worn.
Hmmm... yes it happens. I believe the game doesn't use that multiplier and it only appears in leather, no other type of fabric has it.
Reported to Mantis:
https://ludeon.com/mantis/view.php?id=1629 (https://ludeon.com/mantis/view.php?id=1629)