How do you sell a website? If its being hosted do you have to give the buyer your hosting account? Or what? How does it work?
You will have to offer the buyer to host on the same host or to move it to a new host. if the buyer wants to host it on a new server, you will have to help transfer all the files and set it up on a new server. If the buyer wants to stay with your host, you will have to then provide your hosting info. Then inform your host of the new persons information so they can bill him/her.
Depending on how much it costs. You may consider using escrow.com just to be safe the seller doesn't pay up.