I like how shiva has it... even if you don't get a drop you get a token that you can use to upgrade the drop that you do get. I would put it on about the same. Token item +1chest+%chance of another chest so one guranteed drop and one % drop and the token item - and if it sticks with 4 raids in a set that would be 4 tokens per week - I'd say 20 tokens would be required per piece.