I just got one from Scuderia Systems in Egham. Suggest you contact Jack there - he may be able to cut you a deal as the euro exchange rate is good right now. Personally I'd go with new because you need the right mounting brackets etc....
Should have said - I also spoke to this guy - you may be interested - but I thought new was a better deal.... Ferrari F430 Scuderia Sports Capristo Exhaust | eBay
