You have to factor in the effort required to extract the part and the value of what remains. In the extreme, a hog ring is pretty difficult to get to and removing it significantly decreases the value of an otherwise serviceable seat, so using dealer values as a basis is pointless. On the other hand, better to get a buck for something from the only interested buyer than nothing from scrapping it.

That probably wasn't very useful

Call scrap yards to determine actual retail values.

Sixto
95 S420
87 300SDL
83 300SD