How long is a piece of string! hehehe

Depends on a couple things :

a) are you going to have original parts (ie original turbo / intercooler) or go for uprated parts? GRS / Samco hoses etc...

b) buying it in bits / one lot

If you buy it in bits it is probablly gonna cost you more. I think your best bet would be to try and find a rotten out S2 and see if you can get it for a couple hundred quid, that way everything you will need will be there.

I reckon your looking anywhere between £200 - £1500, depending on buying it in bits / whole etc... / new parts etc...

CheeRS