I agree with Onyx. And these guys are evolving their scams every day, so that get more people to fall for it.
I know someone that did the online ABSA detail verification scam thing. They are knowledgeable enough to see the obvious ones, but not enough to check that the link they are clicking is NOT and ABSA link, even though everything looks to be on the up and up. They lost R150 000 in the process.
But yes, deal with people you trust and know. People that have a reputation for good service. It makes it hard for new comers to be trusted, but in time, if you stick around, people will trust you as well.
I am also on the carbonite classifieds forum. And there we have an iTrader system, where you can rate people based on the service they give. Perhaps we can do something on here as well.