do it your self - (barring setting the plug gap, if you've never done it before, it is a 15 minute job) a plug, 4 screws (lift) and the 4 spark plugs; repeat in reverse
sorry to say (and i have learned from experience) about 60k miles Both things have to be replaced - its best - for the car and the possible headaches if you don't
you can get a 'kit' on line for about 250. 00 comes with the DIC and plugs - it is one of the easiest things to do -
there is even video on the site that tells you how to do it ...
the biggest concern is getting the right DIC for your SAAB -
don't know what a dci is. I just had power steering hoses and spark plugs replaced for under 300,in Massachusetts. Had engine diagnostics checked at Advance Auto said Oxygen Sensor. Code disappeared after a day, hasn't ret'd.