I've only read through part of the topic, but in general the first step is indeed for buyers to watch out themselves and keep themselves up to date on 'the trends of scamming.'
However, I can understand it's still an unwanted phenomenon on your forum. You want a safe, free trading environment, and you don't want the 'spam' feel that these scams and crazy offers often feel like (at least to me).
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Could you perhaps make a system where members below say 100 posts (
and have been member for less than a month) pay a small fee to enable entrance to the trade section? (i.e 5GBP fee per year+1GBP per topic as long as you stay under this amount of posts).
This rule will enable new members access to the trading section if they really need/want to sell something, but at a charge to prevent scammers (with fresh/new accounts) from getting in.
People who make a 100 posts or more and use the account for more than a month usually are people who have more business on the forums than just selling stuff, and are people who have interest in a good reputation.
In addition to this you could perhaps make more easy referral to the trader feedback (when you click a member's name, in the dropdown menu a button saying 'see trader feedback' - meaning EVERY member will have 1 trader feedback topic accessed in the click of a button), and if someone has a perfect or a very bad trading reputation, mark it on their profile?
Also as a last thing, for long time/term members who have gotten bad feedback (and it's backed up that it was a scam or bad sale), you could charge them for next sales before banning them from the trading section altogether if they scam again?
I know these are all pretty serious ideas and it is a pretty serious/heavy subject, but I'm just throwing some ideas out there
