The value of your script may depend on its condition. If it is in at least good to very good in that regard, I would say that, realistically, you could expect to earn from between $200-$400 if sold "on the street." The lower figure, or near it, would be realistic, and the higher figure a bit on the less realistic side. I personally have bought six Charlie Chan original scripts, and I have paid on average about $250 per script.