I paid $3000 for my 98 Sentra base model with 50,000 , but I had some door damage on mine. The car's value was based on dealer trade in rather rather then private sale trade. As in why bother selling the car to a dealer for $3000 when you can get someone else to buy it for more.
This is just to give you some idea what others are paying.
Nada guides (
www.nadaguides.com) says average retail is $4,625. It also says a $600 bonus for the low milage. This is just an average price and doesn't take into account condition.
Personaly I'm a private party person. While dealers can be helpful, private parties are far more likely to have accurate information as to repairs and maintance.