I was looking earlier this year for mine, the cheapest I found availale for a standard exhaust was actually a VX dealer, mainly because all the other places said they had to buy it from the main dealer before fitting it. I was quoted over £700 for cat back as the cheaest, but manaed to get a performance exhaust for about £450 fully fitted. Was well worth the money as well

'99 3.2V6 Auto Limited.
Some day it will be how I want it to be...