[PushingMyLuck]

Here are 4 more that are about $20k.

$21k for 1985 with 102k miles
Excellence :: Porsches for Sale : 1985 911 Targa for sale in Chico, CA

$21k for 1986 with 116k miles
Excellence :: Porsches for Sale : 1986 911 for sale in Phoenix, Arizona

$21,500 for 1985 with 128k miles (coupe)
Excellence :: Porsches for Sale : 1985 911 Carrera for sale in Pembroke Pines, Florida

$20k for 1986 with 169k miles (coupe)
Excellence :: Porsches for Sale : 1986 Porsche 911 Carrera Coupe for sale in Charlottesville, VA region