Michael,
$15 might be too much to ask for that particular model as it's pretty cheap to get one brand new, especially if you watch for sales or use a coupon. I picked one up a few months back for $10 + shipping from Compasseco. Now granted that was a short term deal, but I see them now going for $30 with free shipping plus they'll throw in another for $10 extra. You'd have to almost pay someone to take it off of your hands in order to compete with that kind of price.
My advice? Use it as a guinea pig for learning something interesting such as carving a new stock or any old project for which you don't want to a good gun. I'm going to use mine as the test bed for learning how to make leather breech and piston seals as well as carving a new stock. At some point, I'll try out different ways to fabricate a better set of sights that won't cause the pellets to hit 5" high when shooting at 10 meters :-)