"Do you really wish to know?" — Spoilers from the books and/or adaptations to follow!
Additional goods or valuable ingredients are items Geralt can obtain from the remains of beasts he has killed. They lack alchemical uses but some merchants will pay for them, and some quests require them. They do not usually require journal bestiary entries in order to be "available" to Geralt, unlike other skin-able items which do have alchemical uses. Below is a quick list of all the additional goods in the game and the best prices (remember, not every merchant gives the best price).
| Image | Name | Quest | Buyer(s) | Buy | Sell |
|---|---|---|---|---|---|
|
Barghest skull | 
|
|
10 
|
10
|
|
Basilisk hide |
|
|
10
|
10
|
|
Chitinous carapace |
|
10
|
10
| |
|
Fleder fang |
|
|
10
|
10
|
|
Squirrel puff |
|
|
– | – |
|
Wolf pelt |
|
|
5
|
5
|
|
Wyvern egg |
|
|
15
|
3
|
|
Wyvern meat |
|
|
25
|
5
|