£150 pounds sounds like a lot of money just to fit the pump buddy.
Diesels are rascals if not looked after properly, so make sure you do some long journeys and give the car a good fuel clean with BG 44K Diesel cleaner, there is a link on here somewhere for you to go too to buy it. Bottom line, the SAAB diesel is a great car but fussy if neglected and not shown the love. I will do what I can to help & advise but you MUST get the car engine system read by a Tech II with the SAAB software. Yes there are generic fault code readers, but the SAAB version interrogates the system more in depth and will save you money on incorrect guess work that could cost you a small fortune.