It's in three bits, one large piece that bolts on to the head and the block which is the inner cover, the outer cover which clips on to that bit and the bit I think you are talking about that is the lower inner piece that sits around the crank pulley. At a guess I'd say it would cost between 10 and 20 quid bearing in mind what the other bits cost. I can't get on Vagcat atm or I'd be able to get the pno.