I picked "trade it in"
I'll tell you why..
I have found that replacing parts on an older Bonneville is very difficult. Those lenes and taillights are a b*tch to find. The electronic systems are beginning to go on the fritz, so that gets very spendy $$ very fast. The value to fix it is not equal to the value to trade it in (getting what you can) and picking up a more reliable 94.
There is a guy on this forum ...Tonyrodz I think; who has a whack of SSE parts for sale. You may want to keep the car if the following is true: low mileage, no rusting, good brakes, wheels, bearing and doesn't leak fluids. If you are mechanically inclined like some are on the forum, then this can be a great project car for you to restore
I debate this relentlessly, I want a 97 SSEi, but I can't do it right now, so I'm fixing what I can on my 89 and sticking with that. See, it also depends on your financial situation and what funds can be diverted to getting a newer car.
Its not an easy decision, but I'm sure you'll figure out something.
BTW...welcome to the forum