Depends where you are in the UK, Stuart?
The Saab Owners Club (SOC) Mag (DRIVER) advertises Stainless Exhausts on a SOC scheme from around £275 (From CAT back, although yours won't have a CAT), but you'd need to fit it yourself or pay extra.
Cardiff/Bristol 'Longlife Exhausts' can build you a quality system, to your speck and preference, for around £300, including VAT & fitting.
They did a good job on my CSE, and it comes with a lifetime warranty. Beats 3 years from a Std Saab system or other cheeper alternative - so long as you intend to keep your beloved Saab!