Grand Prix GT for sale

I am going to sell my much beloved Grand Prix GT this coming summer, how much should I be looking for as a sale price?  I have just over 140,000Kms on it and have had not a stitch of trouble with the car.  The usual scratches on the rear bumper and the headlamps are pitted so bad from rocks that the dims are virtually useless, but otherwise this is a strong car.  I have the HUD, Bose sound, and sunroof.  The cloth interior is like new except for the passenger seat which has 3 cigarette burns from my drunk girlfriend a few years back (other than that night this car has never been smoked in).  I still have the original windshield in and plan to have it replaced before selling.  I am really gonna miss this car - it has been a real solid car and never needed anything other than regular maintenance.