Computer help!?

[ahhhhitsmel]

Hello, newbie here.

I was hoping to get some opinions and insight regarding my dear car.

I have a 1992 Saab 9000 Turbo CD (named Sven.) He has had a lot of work put into him and up until recently, was running wonderfully. He has a new transmission, alternator, brakes, and so forth and so on. And aside from a small oil leak, was in great condition.

That is, until, he refused to start. I stopped at a store real quick, and when I came out and tried to start him, he tried to crank over but just wouldn't turn. I have taken him to two mechanics. The first one diagnosed him with needing a new computer. The problem is, I can't afford to get a brand new computer and both mechanics have been unable to find the correct used computer.

I was wondering if a) the diagnosis sounds correct and it is the computer that needs to be replaced and b) if finding a used one for him is feasible and if so, should I go to a foreign auto expert or a dealer or what?

Any opinions, relative experiences, and insight would be greatly appreciated.

THANKS.