http://supercell.com/en/terms-of-service/
The terms explicitly say
You shall not sell, rent or give away your Account, create an Account using a false identity or information, or on behalf of someone other than yourself; You shall not use the Service if you have previously been removed by Supercell, or previously been banned from playing any Supercell game;.
Do not attempt to try to buy or sell accounts here anymore, you will receive a ban (on Toribash).