81 Porsche 911 question
 

I'm looking at buying an 81 porsche 911 sc targa top with 90,000 miles. The interior needs to be redone and there is a small dent under the front bumper. Other than that. The car is great. Garage kept from the previous owners. It runs fantastic for an 81. This will be my first porsche. I was wondering what would be a fair price for it? Nada it says 18,100 for fair. But I just can't see spending 18,000 on an 81. Oh and it's all original. No mods at all.