Instead of just throwing material cost into weapons that didn't have them before, why not make it where you can use them to get special items that weren't already in the game. In put an example/idea down below-
In Red Leaf Hills, there will be a woman sitting on a bench who can make you a cape. Although it is free of charge, you need to get the resources to make it yourself.
Materials Required-
30 Rafflesia Leafs
Description:
A thick cape that is both comfortable and surprisingly durable. It gives a great boost in Archery.
Stats- (Lv.12)
Defense: 15
Archery: 8
Armor Type: Accessory