Twice in my life I've been in the position of making a major repair to a car, which would cost almost the car's worth, and I've decided to go ahead and do it. Twice, now, the car has died within a few weeks of that decision. (Well, more accurately, once it died and once I killed it in an accident.)
I think the universe is trying to tell me something- trash old cars when they're almost dead, don't try to eek out a few more years.
Anyone had experience with eBay motors? I've heard good things from a few folks.