Hello there, second post here so far.
I am not 100% sure this works after recent patch, has not been abel tro try it since..hope someone can verify or tell me it doesnt work after this.
1. You need to be in a raidguild, wich got a guildbank. You need the "guild amount" for repairs.
2. no number two? nope!
so, i raided KZ with a new started guild, i was MT, we came up to Prince but we whiped as little n00bs there.
My gear got all red, and since i was MT it would cost like 40-50g.
But after the raid was disbanded, the guild repair feature on vendors, said 0copper for repairs.
I pressed the button anyway, and wtf? I didnt had too pay a shit for it, and guild bank didnt either.
So u need to be in guild wich used a raid group, then u might be able to use this feature if it still works.
Delete if it doesnt work