[Robert Adams]

I think if you do a search in this forum you will find quite a few references on the how-tos of buying a 1st Porsche.
PCA.ORG has a shopping list of questions to keep in mine. It's free. Excellence Mag on line also has some free guidelines and open to discussion price guidelines for specific models and years.
2nd decide what your intentions are in buying the car, weekend, daily, DE, etc. If you are driving as a daily or DE a pristine low miles example is a waste of money in my opinion. But one with so so to high miles (125k) with records is worth more to me. Next buy the latest model you can afford unless you are into vintage.
Next up is do all the research you can. One thing will lead to another, you'll be amazed.
As for the 1st example you posted?? The accident and the seats are enough for me to pass unless they were to drop the price $5k which I doubt they are willing to do. Plenty of good clean cars out there for a fair price in all sizes and years...keep looking and go see as many as possible so you know a good one when you see one and which model you want. Buying a Porsche is not like going out and buy any old 'used' car. I found the search is as much fun as the buying, but you can get fatigued and frustrated, but the right car for you will be worth it all. When you check the PCA.ORG site they also list events occurring by region such as shows, concours, etc and are listed with dates and location. Go to a few, it's a good way to kick a lot of tires in one convenient place. Most owners will talk your head off if you ask a few questions about their car/model.
Good luck! Keep us posted. We collectively will not let you buy a lemon!