Anything you own you can sell. You legally can't distribute duplications of the media. And obviously I wouldn't sell to anyone under 18...but as stated you buy something you own it, and you have the right to resell it.
In the state of Oklahoma is it illegal to own porn? I have heard so many rumors about you can have it but it cannot be XXX. Of course everyone is over the age of 18, but i'm just curious, b/c I know Oklahoma laws are very different with porn that other states.