It's only worth what someone will pay for it. List it at a price you think is reasonable and see if it sells. If it hasn't sold after a few months, relist it with a lower price. Given that there is some pokemon thing going on at the moment, I'd probably list it as an auction. Have the start price the lowest your're willing to accept, e.g $19.99. Don't forget to make sure you have the correct postage cost in the listing too.
