Heres my opinion:
I would weigh the costs of fixing it versus the costs of what you would get in trade and what you would have to spend extra on the trade.
Generally I think a benz is a great investment if it doesn't need a lot to get it back to good shape.
If the engine runs great, and everything else is ok, then I would think the minor cosmetic expense, the ball joints and the trans leaks could be done for a decent price.
Since you are in GA, you could head on down to see benzmac and have him do the mechanical repairs. he's in Atlanta if I am correct or at least near it.
You didn't say what you were planning on trading it for, that might help us help you make the decision.
If it were me and overall the car was in good shape, I'd keep it and save up for an extra car to have as a toy.