Debating if I should sell my 01 Cobra

I bought the 01 Cobra when I saved up for it my first year teaching because it was my dream car. I've babied it throughout the years and have only put 37K miles on it, since I have had another car to use as my daily driver.

Well, the other day, someone left a note on my car saying that they wanted to buy it? Now I'm in a dilemma on what I should do. I've flirted with the idea of selling it since I recently started going back to college. My reason for not putting it for sale was because with the age, I know I wouldn't get much out of it, even though to me it's worth more. Edmunds has it priced at $13-15K. Does anyone know what a good price to ask for it would be? Should I just let the buyer make an offer and go from there?

The guy who offered to buy it was some flakey weirdo. I should have known since he left a note on my car saying he wanted to buy the car. I thought it would be some collector who knew what the car was. The guy didn't even have a clue. Says he was looking for something cheap for his sister, which just sounds weird as it is. When I said it was a Cobra, he asked "It's a Ford Mustang right?" At that point I just quoted him $20K, since I knew he wouldn't buy it, and just left it at that. Having the car as long as I have the blue book priceisn't near what it's worth to me personally. It was my dream car and I saved my whole first year teaching to buy it. Now I'm in my 10th year teaching and the car still drives like a dream, so this whole ordeal just made me realize I could never sell the car