FYI - Sedo ToU are clear when it comes to listing a domain on their service. Refusing to sell a listed domain (one owns) is a violation. I'd be interested to see how this holds up in court.
(d) As a Seller of a Domain listed on the Domain Marketplace and/or Auction, you represent and warrant that: (i) you have registered, or have the exclusive right to register, the Domain with an appropriate Domain registrar or other registration authority; (ii) your registration rights to the Domain are current and not subject to deletion, cancellation, rescission, or deactivation by any applicable Domain registrar or other registration authority; (iii) you have not taken any action that would impair your ability or right to transfer the Domain registration right and no such action has been taken against you; (iv) the Domain has not been used in such a manner as to infringe the rights of any third party, including, but not limited to, trademark, naming or publicity rights; (v) the Domain is not the subject of any legal disputes or proceedings challenging your right to register or use the Domain; (vi) you will accurately describe the subject listing; (vii) you own and have the right to sell the content, if applicable, that you have included in your listing as part of your Domain; and (viii) if your offer to sell and transfer the Domain is accepted, you will complete the transaction with a ready, willing, and able Buyer. You will not, under any circumstances, list or transfer the rights to any Domain that you do not have sufficient rights to transfer, or that is illegal to transfer under applicable law.