I vote for registration of members who wishes to sell stuff online - same as what we do for PDA forums at MyPDACafe or KVPUG.
Info must include the following:
1. Name: <must follow I/C>
2. I/C No: <self-explainary>
3. Address: <must be recent>
4. Contact No: <at least 2, a mobile or home/business, must be updated in profile>
5. E-mail: <no free accounts, must be from local ISPs if possible>
As for posting, the following rules:
1. Tag before posting: [WTS] - Wanted To Sell or [WTB] - Wanted To Buy
2. Post bumps: Once per day (this will help to reduce server load)
3. Description of Item: Type it out and don't use web links!
4. Image of Item: Actual images, not stealing from other people's post. Those caught do so will be given 3 warnings. After 3rd warning, member will be barred from selling online.
5. Price: A must!
6. Contact No: Must match with database / profile