Compare it to ores.
on my first play through I ended up selling iron and tenebrium bars because I didn't have a use for them all. I even stopped mining it when I came across them.
Every item upgrade I got was modified by my BS and I never ran out.
Sinew on the other hand, I was able to upgrade 2 ranged weapons the entire game. Never mind crafting a new weapon every few levels.
Rare, absolutely, but should it be?
