These cars have decreased in value to the point where a relatively minor accident and the cost to repair the damage can cause the insurance company to total the car. If all you are going to do is drive the car, then the fact that it was total because of damaged body panels cost more to repair than the cars was worth, wouldn't be much of concern as long as there was no hidden damage. You mentioned that the bumper attachment points are tweaked and that is cause for concern. I would want some proof that the frame is straight.
A well maintained coupe, current on maintenance at about the same mileage and no salvage title might be worth $12,000. From the owners description, it would seem it didn't sell at $9500 so I would be inclined to offer less say $8000 if the frame is straight.
Do not buy this or any other Porsche without having a pre-purchase inspection (<acronym title='pre purchase inspection'>PPI</acronym>) performed by a mechanic knowledgeable about these cars. Search the this forum for <acronym title='pre purchase inspection'>PPI</acronym> information.