The mechanic has told me I have turbo failure on my c320cdi. Cost of turbo from merc circa £1200, he also advised replacing exhaust manifolds ?£600 and air intake has a crack £300 from merc. In addition there is the labour. Is it worth it? When the car is on form it takes some beating. The cost of replacing the turbo is hefty and wonder whether I should simply upgrade to the newer c class??