I was quoted £400 to £450 from memory from a dealer - that was their best price etc with parts 'at cost'. In the end I paid a lot more using a local garage as I needed it sorted asap.
Yep you can do that with pre 2008MY cars. It is a good improvement. I have some blanking plates but as my car is a 2008 MY it wont work with the ECU. Apparently it will be an MOT failure soon....?