I've just replaced mine with a reconditioned turbo last Friday for £600
mine is a 2004 D5 so cost may be slightly different.
Whilst looking around in Birmingham the cost of replacement was consistent with most garages and the turn around 48 hrs for an exchange unit.
As mentioned above - if there is no other damage then definitely worth considering. So far the replacement is doing very well but with a minor issue which should be an easy fix.
https://best-turbos.co.uk
These guys are highly recommended and very helpful over the phone.
I didn't actually use them because they only do turbos - I had some other minor work done so went to a local indy.