You're gonna need them materials when you finally do get armor. I'm glad they are as common as they are. By the way there are more than 3 chests and only one of them you can get anything other than materials in, even though you usually get mats anyway. I haven't got any raid armor either, just weapons, and I've done it a lot more than 5 times across multiple characters. But I have fun while doing it and if I got all the armor in just a few goes then there would be no point to keep doing it.