My turbo replacement was (gulp) £1300! But that was with a new cat too, I imagine if you get the turbo re-conned it will be a lot cheaper, but mine disintegrated! and **** the cat (full of oil)
Local garage sourced the bits and did the job, as opposed to main dealer who wanted, if I remember correctly, nearly £2k for the turbo and £800 for the cat, and that was just the bits!
Also the service parts are pretty pricey, but still great vans