You are better off just selling it locally or taking it back to your LFS for credit. No one is going to pay $40+ in shipping for a $10 fish that is so common that you can find it at any fish or pet store.
LOL okay. I think you are missing the point. Why would someone pay to have one firefish shipped long distance? You can even buy them at Petco. Stick to your local Craig's List or LFS for better results. ;)