I think I know the place Turnip is talking about, you see a sign for "TURBO REPAIRS" on the Welsh Road from Two Mills to Queensferry.
I'm pretty sure its pointing to this place:http://www.turboclinic.co.uk/http://carclinicledsham.com/
If your car is a Peugeot, particularly with the 110bhp 1.6 engine then a replacement turbo will be ruined in a matter of months.
Thats the one I was thinking about Gibbo,turbo clinic only do them on an exchange basis and will not touch them whilst there on the car,He did tell me not to touch the cheap copies from China as they don't last.
I phoned him for a price on a Garret turbo for a Merc sprinter and he said would be as little as £100 upto £300 but I know them and am sure they would of done a first class job.