A thought on how you could handle rare item crafting. Maybe for the rarest of the rare (raid quality items) you need multiple crafters for. Since this is supposed to be a social centric game, in order to craft that "amazing breast plate of awesome" you need 3 smiths who totals xxx crafting level, alongside 2 tailors with xx crafting level.
This would fit into the scheme of the game and also make the item that much more epic, and slightly more difficult.