I bought it at the Classic gaming expo, it is brand new. I bought it becuase I have a loose 7800 unit, but just my luck, the unit is dead. Bought it for $20, you can have it for $15. Obviously these adaptors can be hard to get a hold of. If you want you can have the dead unit too. I can't do paypal anymore so you'll have to send concealed cash. You can ask people like Crush Crawfish that I can be trusted.
Thanks!