Guild Wars 2

Why do you need 50 Elder wood planks for Spirit residue
50 Mithril Ingots for Lump of Mithrillium
50 Cured Thick Leather Squares for Spool of Thick Elonian Cord
BUT
100 Bolts of Silk for Silk Weaving Thread?

Crafting is already so expensive, and given we need to make 6 pieces of armor vs. one or two weapons.

Because when this decision was made, there was so much silk it was almost worthless. It was an attempt to give silk value, which worked. I think it worked well enough for them to revert the change tbh.

It was designed to drain excess silk from the economy, but as with many things done for such purposes its designed to burn more than is created, and then they never go back to balance things later.
Which is why ascended was so insanely expensive.

With the addition of 3 Elonian Leather on top of the 3 Damask for the insignias ascended is just a joke.