That's a loaded question since there are a lot of different aspects to this costume. I used sintra plastic for the armour and a vinyl for the shirt/armour. It wasn't exactly an easy costume to make, so if you're unfamiliar materials/sewing I don't recommend it.
Yooo hoo this is sick man. I was just on a dude's facebook and I saw this Lin cosplayer and was like, "I swear I know this face." Well done guy. Fan Expo went good for me too! Holy cow, only two copies of my manga left!